CN115398848A - Receiving time overlapping with downlink reference signal and channel - Google Patents

Abstract

Systems and methods are provided for determining a Transmission Configuration Indication (TCI) state of an Aperiodic (AP) channel state information reference signal (CSI-RS) overlapping a downlink transmission. In some embodiments, a method performed by a wireless device comprises: receiving an AP CSI-RS in the same symbol as a downlink transmission scheduled by a DCI having two TCI states indicated in the DCI; receiving a trigger for one or more AP CSI-RS with a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource, wherein the scheduling offset is less than a threshold reported by a wireless device; and determining that the downlink transmission is scheduled according to a scheme of receiving different layer sets of the downlink transmission in different TCI states. In some embodiments, the wireless device applies QCL assumptions on PDSCH transmission occasions when receiving AP CSI-RS.

Description

Receiving time overlapping with downlink reference signal and channel

Related applications

This application claims the benefit of provisional patent application serial No. 63/008,386, filed on 10/4/2020, the disclosure of which is incorporated herein by reference in its entirety.

Technical Field

The present invention relates to aperiodic CSI-RS reception when overlapping in time with a Physical Downlink Shared Channel (PDSCH).

Background

NR framework structure and resource grid

NR uses cyclic prefix orthogonal frequency division multiplexing (CP-OFDM) in the Downlink (DL) (i.e., from the network node, gNB or base station to the user equipment or UE) and Uplink (UL) (i.e., from the UE to the gNB). DFT-spread OFDM is also supported in the uplink. In the time domain, the NR downlink and uplink are organized into equal-sized subframes, each 1ms. A subframe is further divided into a plurality of equal duration slots. The slot length depends on the subcarrier spacing. For a subcarrier spacing of Δ f =15kHz, there is only one slot per subframe, and each slot consists of 14 OFDM symbols.

Data scheduling in NR is typically on a slot basis, an example of a 14-symbol slot is shown in fig. 1, where the first two symbols contain a Physical Downlink Control Channel (PDCCH) and the rest contain a physical shared data channel, a Physical Downlink Shared Channel (PDSCH) or a Physical Uplink Shared Channel (PUSCH).

Different subcarrier spacing values are supported in NR. The supported subcarrier spacing values (also referred to as different parameters) are defined by Δ f = (15 × 2) ^μ ) kHz given, where μ ∈ {0,1,2,3,4}. Δ f =15kHz is the basic subcarrier spacing. Slot duration in milliseconds at different subcarrier intervals is given by

ms is given.

In the frequency domain, the system bandwidth is divided into Resource Blocks (RBs); each corresponding to 12 consecutive sub-carriers. RBs are numbered from 0 starting from one end of the system bandwidth. The basic NR physical time-frequency resource grid is shown in fig. 2, where only one Resource Block (RB) within 14 symbol slots is shown. One OFDM subcarrier during one OFDM symbol interval forms one Resource Element (RE).

Downlink transmissions may be dynamically scheduled, i.e., in each slot, the gNB sends Downlink Control Information (DCI) over the PDCCH, which information relates to the UE data to be transmitted and on which RBs and OFDM symbols the data is transmitted in the current or future downlink slot. The PDCCH is typically transmitted in the first few OFDM symbols of each slot in the NR. UE data is carried on the PDSCH.

Three DCI formats, DCI format 1_0, DCI format 1_1, and DCI format 1_2, are defined in NR for scheduling PDSCH. DCI format 1_0 is smaller in size than DCI 1_1 and may be used when the UE is not yet connected to the network, while DCI format 1_1 may be used to schedule MIMO (multiple input multiple output) transmissions with up to 2 Transport Blocks (TBs). NR version 16 (Rel-16) has incorporated DCI format 1 _u2 to support configurable sizes of certain bit fields in DCI.

One or more of the following bit fields may be included in the DCI: frequency Domain Resource Allocation (FDRA); time Domain Resource Allocation (TDRA); a Modulation and Coding Scheme (MCS); new Data Indicator (NDI); redundancy Version (RV); numbering the HARQ process; PUCCH Resource Indicator (PRI); a PDSCH-to-HARQ feedback timing indicator (K1); an antenna port; and a Transport Configuration Indication (TCI).

The UE first detects and decodes the PDCCH, and if the decoding is successful, decodes the corresponding PDSCH based on the decoded DCI carried in the PDCCH. The PDSCH decoding status is sent back to the gNB in the form of HARQ acknowledgement or HARQ-ACK in the PUCCH resources indicated by the PRI. An example is shown in fig. 3. The time offset T1 between the reception of DL DCI and the corresponding PDSCH is determined by the slot offset and the starting symbol of the PDSCH indicated in the TDRA in the DCI. The time offset T2 between the receipt of DL DCI and the corresponding HARQ ACK is provided by the PDSCH-to-HARQ feedback timing indicator in the DCI.

Time domain resource allocation

When the UE is scheduled by DCI to receive PDSCH, a Time Domain Resource (TDRA) allocation field value m of the DCI provides a row index m +1 for a time domain resource allocation table. When DCI is detected in the UE-specific search space, the PDSCH time domain resource allocation is made according to the RRC-configured TDRA list listed in the RRC parameter PDSCH-timedomainnalocallist provided in the UE-specific PDSCH configuration PDSCH-Config. Each TDRA entry in the TDRA list defines a time slot offset K between the PDSCH and the PDCCH that schedules the PDSCH ₀ A start and length indicator SLIV, a PDSCH mapping type (type a or type B) to be assumed in PDSCH reception, and an optional repetition number RepNumR16.

TCI State

The demodulation reference signal (DM-RS) is used for coherent demodulation of the PDSCH. The DM-RS is confined in the resource blocks carrying the associated PDSCH and mapped onto the allocated Resource Elements (REs) of the OFDM time-frequency grid in the NR so that the receiver can efficiently process time/frequency selective fading radio channels. One PDSCH may have one or more DMRSs, each associated with one antenna port. An antenna port for the PDSCH is indicated in DCI scheduling the PDSCH.

Several signals may be transmitted from different co-located antenna ports. These signals may have the same large scale properties when measured at the receiver, for example in terms of doppler shift/spread, average delay or direction of arrival. These antenna ports are then referred to as quasi co-located (QCL). The network may then signal to the UE that both antenna ports are QCLs. If the UE knows that both antenna ports are QCL with respect to a particular parameter (e.g., doppler spread), the UE may estimate the parameter based on a reference signal transmitted on one antenna port and use the estimate when receiving another reference signal or physical channel on the other antenna port. Typically, the first antenna port is represented by a measurement reference signal (referred to as source RS), such as a channel state information reference signal (CSI-RS), and the second antenna port is a DMRS (referred to as target RS) for PDSCH reception.

In NR, QCL relationship between demodulation reference signals (DMRS) and other reference signals in PDSCH is described by Transmission Configuration Indicator (TCI) state. Depending on the UE's capabilities, up to 128 TCI states in the NR frequency range 2 (FR 2) and up to 8 TCI states in the NR frequency range (FR 1) may be configured for the UE through Radio Resource Control (RRC) signaling. Each TCI state contains QCL information for purposes of PDSCH reception. In DCI scheduling PDSCH, one or two TCI states may be dynamically signaled to the UE in the TCI field.

The QCL relationship between DMRS and other reference signals in PDCCH is described by TCI status of the control resource set (CORESET) transmitting PDCCH. For each CORESET configured to the UE, the TCI state list is RRC configured; one of which is activated by MACCE. In NR Rel-15, a maximum of three CORESET per bandwidth part (BWP) may be configured for the UE. In NR Rel-16, up to five CORESET per BWP may be configured for the UE, depending on the capabilities.

Certain challenges currently exist. The existing NR standard defines UE behavior when PDSCH is indicated in a single TCI state when aperiodic CSI-RS collides with PDSCH. However, in other cases when the aperiodic CSI-RS collides with the PDSCH, the UE behavior is not defined. Therefore, improvements in handling collisions are needed.

Disclosure of Invention

Systems and methods are provided for determining a Transmission Configuration Indication (TCI) state of an Aperiodic (AP) channel state information reference signal (CSI-RS) overlapping with a Physical Downlink Shared Channel (PDSCH) transmission. In some embodiments, a method performed by a wireless device for determining a TCI state for receiving one or more AP CSI-RSs comprises one or more of: receiving one or more AP CSI-RSs in the same symbol as a downlink transmission scheduled by a DCI having two TCI states indicated in the DCI; receiving a trigger for one or more AP CSI-RS with a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource, wherein the scheduling offset is less than a threshold reported by a wireless device; and determining that the downlink transmission is scheduled according to one of the group consisting of: "TDM scheme a (TDMSchemeA)"; "FDM scheme a (FDMSchemeA)"; "FDM scheme B (FDMSchemeB)"; and schemes in which different layer sets of downlink transmissions are received in different TCI states. In some embodiments, the wireless device applies QCL assumptions on PDSCH transmission occasions when receiving AP CSI-RS, as appropriate.

In some embodiments, a method performed by a base station for indicating a TCI status for receiving one or more AP CSI-RSs comprises one or more of: transmitting, to a wireless device, one or more AP CSI-RSs in the same symbol as a downlink transmission scheduled by a DCI having two TCI states indicated in the DCI; triggering one or more AP CSI-RS with a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource, wherein the scheduling offset is less than a threshold reported by a wireless device; and scheduling downlink transmissions according to one of the group consisting of: "TDM scheme A"; "FDM scheme a"; "FDM scheme B"; and schemes in which different layer sets of downlink transmissions are received in different TCI states. In some embodiments, the base station assumes that the wireless device applies QCL assumptions on PDSCH transmission occasions when receiving AP CSI-RS, as appropriate.

Certain embodiments may provide one or more of the following technical advantages. When the aperiodic CSI-RS collides with the PDSCH, the proposed solution defines the UE behavior (i.e., what QCL assumption the UE makes) to receive the aperiodic CSI-RS when both TCI states are used to indicate the PDSCH. One benefit is that the proposed solution defines which QCL properties should be used to receive conflicting aperiodic CSI-RS, which was not previously defined in NR. With the proposed solution, aperiodic CSI-RS can be flexibly triggered in overlapping symbols, where PDSCH is scheduled according to one of NC-JT schemes "FDM scheme a", "FDM scheme B", and "TDM scheme a" based on a single PDCCH.

In some embodiments, the downlink transmission comprises a PDSCH transmission. In some embodiments, the threshold reported by the wireless device comprises a beamSwitchTiming value.

In some embodiments, the PDSCH is scheduled according to one of the group consisting of: "FDM scenario a"; "FDM scheme B"; and different layer sets of PDSCH received in different TCI states. In some embodiments, a scheduling offset from a last symbol of the PDCCH to a first symbol of the PDSCH is greater than or equal to a threshold timeduration format qcl.

In some embodiments, when the single triggered AP CSI-RS is in the same symbol as the PDSCH, the method further comprises the wireless device applying the QCL assumption given by the first indication TCI state in the DCI of the PDSCH when receiving the AP CSI-RS. In some embodiments, when the two triggered AP CSI-RS are in the same symbol as the PDSCH, the method further comprises the wireless device applying QCL hypotheses given by the first and second indication TCI states in the DCI of the PDSCH, respectively, when receiving the first and second AP CSI-RS.

In some embodiments, the first triggered AP CSI-RS and the second triggered AP CSI-RS are according to an ordering of the corresponding CSI-RS resource identifiers or an ordering of the corresponding CSI-RS resource set identifiers to which the two AP CSI-RS belong. In some embodiments, a scheduling offset from a last symbol of the PDCCH to a first symbol of the PDSCH is less than a threshold timeduration format.

In some embodiments, when the single triggered AP CSI-RS is in the same symbol as the PDSCH, the method further comprises the wireless device applying the QCL assumption given by the first default TCI state of the PDSCH when receiving the AP CSI-RS. In some embodiments, when the two triggered AP CSI-RSs are in the same symbol as the PDSCH, the method further includes the wireless device applying QCL assumptions given by the first and second default TCI states of the PDSCH, respectively, when receiving the first and second AP CSI-RSs.

In some embodiments, the first triggered AP CSI-RS and the second triggered AP CSI-RS are according to an ordering of the corresponding CSI-RS resource identifiers or an ordering of the corresponding CSI-RS resource set identifiers to which the two AP CSI-RS belong.

In some embodiments, the PDSCH is scheduled according to "TDM scheme a". In some embodiments, a scheduling offset from a last symbol of the PDCCH to a first symbol of the first PDSCH transmission occasion is greater than or equal to a threshold timeduration format cl. In some embodiments, when the single triggered AP CSI-RS is in the same symbol as the first PDSCH transmission occasion, the method further comprises the wireless device applying a QCL hypothesis given by a first indication, TCI, state in DCI of the first PDSCH transmission occasion when receiving the AP CSI-RS. In some embodiments, when the single triggered AP CSI-RS is in the same symbol as the second PDSCH transmission occasion, the method further comprises the wireless device applying the QCL hypothesis given by the second indicated TCI state in the DCI of the second PDSCH transmission occasion when receiving the AP CSI-RS.

In some embodiments, the scheduling offset from the last symbol of the PDCCH to the first symbol of both the first and second PDSCH transmission occasions is less than a threshold timeDurationForQCL. In some embodiments, when the single triggered AP CSI-RS is in the same symbol as the first PDSCH transmission occasion, the method further comprises the wireless device applying, when receiving the AP CSI-RS, a QCL assumption given by a first default TCI state in DCI of the first PDSCH transmission occasion. In some embodiments, when the single triggered AP CSI-RS is in the same symbol as the second PDSCH transmission occasion, the method further comprises the wireless device applying the QCL hypothesis given by the second indicated TCI state in the DCI of the second PDSCH transmission occasion when receiving the AP CSI-RS.

Drawings

The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present invention and, together with the description, serve to explain the principles of the invention.

Fig. 1 illustrates data scheduling in NR, typically on a slot basis, an example showing a slot of 14 symbols, where the first two symbols contain a Physical Downlink Control Channel (PDCCH) and the rest contain a physical shared data channel, i.e. a Physical Downlink Shared Channel (PDSCH) or a Physical Uplink Shared Channel (PUSCH);

figure 2 shows a basic NR physical time-frequency resource grid;

fig. 3 illustrates an example in which PDSCH decoding status is sent back to the gNB in the form of HARQ acknowledgements in the PUCCH resources indicated by the PRI, in accordance with some embodiments of the invention;

FIG. 4 illustrates one example of a cellular communication system in which embodiments of the invention may be implemented;

fig. 5 illustrates locations where data is transmitted to a UE through two TRPs, each TRP carrying one TB mapped to one codeword, in accordance with some embodiments of the present invention;

FIG. 6 illustrates an example relationship between TCI states and DM-RS CDM groups for a multiple PDCCH, multiple TRP scenario, in accordance with some embodiments of the present invention;

fig. 7 illustrates one example of PDSCH transmission on two TRPs using a single DCI in accordance with some embodiments of the present invention;

fig. 8 illustrates an example of multiple TRP PDSCH transmissions using FDM scheme a in accordance with some embodiments of the invention;

FIG. 9 illustrates an example data transmission using FDM scheme B, where PDSCH #1 is sent in PRG {0,2,4} from TRP1 and PDSCH #2 with the same TB is sent in PRG {1,3,5} from TRP2, in accordance with some embodiments of the invention;

fig. 10 illustrates an example data transmission using TDM scheme a, where PDSCH repeats occurring in a small slot of four OFDM symbols within a slot, in accordance with some embodiments of the present invention;

fig. 11 illustrates an example multi-TRP data transmission with a timeslot-based TDM scheme in accordance with some embodiments of the present invention;

fig. 12 illustrates an example of CSI-RS REs for 12 antenna ports, showing 1 RE per RB per port, in accordance with some embodiments of the present invention;

fig. 13 illustrates a method performed by a wireless device for determining a TCI status for receiving one or more AP CSI-RSs, in accordance with some embodiments of the present invention;

fig. 14 illustrates a method performed by a base station for indicating TCI status for receiving one or more AP CSI-RSs, in accordance with some embodiments of the present invention;

fig. 15 shows an example of embodiment 1 considering collision of AP CSI-RS with PDSCH scheduled according to "TDM scheme a" according to some embodiments of the present invention;

fig. 16 shows a second example of embodiment 1 considering collision of AP CSI-RS with PDSCH scheduled according to "TDM scheme a" according to some embodiments of the present invention;

fig. 17 shows a first example of embodiment 2 considering collision of AP CSI-RS with PDSCH scheduled according to the "TDM scheme a";

fig. 18 shows a second example of embodiment 2 considering collision of AP CSI-RS with PDSCH scheduled according to "TDM scheme a" according to some embodiments of the present invention;

fig. 19 shows a first example of embodiment 3 considering collision of AP CSI-RS with PDSCH scheduled according to "TDM scheme a" according to some embodiments of the present invention;

fig. 20 shows a second example of embodiment 3 considering collision of AP CSI-RS with PDSCH scheduled according to "TDM scheme a" according to some embodiments of the present invention;

fig. 21 shows a first example of embodiment 4 considering collision of an AP CSI-RS with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme, wherein a first TCI state is assumed for the AP CSI-RS, in accordance with some embodiments of the present invention;

fig. 22 shows a second example of embodiment 4 considering collision of AP CSI-RS with PDSCH scheduled according to single PDCCH based NC-JT scheme, wherein first and second TCI states are assumed for the first and second AP CSI-RS, respectively, according to some embodiments of the present invention;

fig. 23 shows a first example of embodiment 5 considering collision of an AP CSI-RS with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme, wherein a first default TCI state is assumed for the AP CSI-RS, according to some embodiments of the invention;

fig. 24 shows a second example of embodiment 5 considering collision of AP CSI-RS with PDSCH scheduled according to single PDCCH based NC-JT scheme, wherein first and second default TCI states are assumed for the first and second AP CSI-RS, respectively, according to some embodiments of the present invention;

figure 25 is a schematic block diagram of a radio access node according to some embodiments of the present invention;

fig. 26 is a schematic block diagram illustrating a virtualized embodiment of a wireless access node in accordance with some embodiments of the invention;

fig. 27 is a schematic block diagram of a wireless access node according to some other embodiments of the present invention;

fig. 28 is a schematic block diagram of a wireless communication device in accordance with some embodiments of the present invention;

fig. 29 is a schematic block diagram of a wireless communication device according to some other embodiments of the present invention;

fig. 30 is a communication system according to an embodiment comprising a telecommunications network, such as a 3 GPP-type cellular network, comprising an access network, such as a RAN, and a core network according to some other embodiments of the present invention;

figure 31 shows an example implementation according to an embodiment of a UE, a base station and a host computer according to some other embodiments of the invention;

FIG. 32 is a flow diagram illustrating a method implemented in a communication system according to one embodiment;

FIG. 33 is a flow diagram illustrating a method implemented in a communication system in accordance with one embodiment;

FIG. 34 is a flow diagram illustrating a method implemented in a communication system according to one embodiment; and

fig. 35 is a flow diagram illustrating a method implemented in a communication system in accordance with one embodiment.

Detailed Description

The embodiments set forth below represent the information that enables those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the invention and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the invention.

The radio node: as used herein, a "radio node" is a radio access node or a wireless communication device.

A radio access node: as used herein, a "radio access node" or "radio network node" or "radio access network node" is any node in a Radio Access Network (RAN) of a cellular communication network for wirelessly transmitting and/or receiving signals. Some examples of radio access nodes include, but are not limited to, base stations (e.g., a New Radio (NR) base station (gNB) in a third generation partnership project (3 GPP) fifth generation (5G) NR network or an enhanced or evolved node B (eNB) in a 3GPP Long Term Evolution (LTE) network, high power or macro base stations, low power base stations (e.g., micro base stations, pico base stations, home enbs, etc.), relay nodes, network nodes implementing portions of the functionality of a base station (e.g., a network node implementing a gNB central unit (gNB-CU) or a network node implementing a gNB distributed unit (gNB-DU)) or network nodes implementing portions of the functionality of some other type of radio access node.

A core network node: as used herein, a "core network node" is any type of node in the core network or any node that implements core network functions. Some examples of core network nodes include, for example, a Mobility Management Entity (MME), a packet data network gateway (P-GW), a Service Capability Exposure Function (SCEF), a Home Subscriber Server (HSS), and so on. Some other examples of core network nodes include nodes implementing access and mobility management functions (AMFs), user Plane Functions (UPFs), session Management Functions (SMFs), authentication server functions (AUSFs), network Slice Selection Functions (NSSFs), network opening functions (NEFs), network Functions (NF) storage functions (NRFs), policy Control Functions (PCFs), unified Data Management (UDMs), etc.

The communication device: as used herein, a "communication device" is any type of device that can access an access network. Some examples of communication devices include, but are not limited to: a mobile phone, a smartphone, a sensor device, a meter, a vehicle, a household appliance, a medical instrument, a media player, a camera, or any type of consumer electronics product, such as but not limited to a television, a radio, a lighting device, a tablet, a laptop, or a Personal Computer (PC). The communication device may be a portable, handheld, computer-included, or vehicle-mounted mobile device capable of communicating voice and/or data over a wireless or wired connection.

A wireless communication device: one type of communication device is a wireless communication device, which may be any type of wireless device that can access (i.e., be served by) a wireless network (e.g., a cellular network). Some examples of wireless communication devices include, but are not limited to: user Equipment (UE), machine Type Communication (MTC) devices, and internet of things (IoT) devices in a 3GPP network. For example, such a wireless communication device may be or may be integrated into a mobile phone, a smartphone, a sensor device, a meter, a vehicle, a household appliance, a medical instrument, a media player, a camera, or any type of consumer electronics, such as, but not limited to, a television, a radio, a lighting apparatus, a tablet, a laptop, or a PC. The wireless communication device may be a portable, handheld, computer-included, or vehicle-mounted mobile device capable of communicating voice and/or data over a wireless connection.

A network node: as used herein, a "network node" is any node that is part of a RAN or core network of a cellular communication network/system.

Note that the description given herein focuses on 3GPP cellular communication systems, and thus 3GPP terminology or terminology similar to 3GPP terminology is often used. However, the concepts disclosed herein are not limited to 3GPP systems.

Note that in the description herein, the term "cell" may be referred to; however, especially with respect to the 5G NR concept, beams may be used instead of cells, and it is therefore important to note that the concepts described herein are equally applicable to cells and beams.

Fig. 4 shows an example of a cellular communication system 400 in which embodiments of the invention may be implemented. In the embodiments described herein, the cellular communication system 400 is a 5G system (5 GS) including an NR RAN or an LTE RAN (i.e., evolved universal terrestrial radio access (E-UTRA) RAN). In this example, the RAN includes base stations 402-1 and 402-2, which are referred to as gnbs in a 5G NR (e.g., an LTE RAN node connected to a 5G core (5 GC) is referred to as gn-eNB), to control corresponding (macro) cells 404-1 and 404-2. Base stations 402-1 and 402-2 are collectively referred to herein as base stations 402 and individually as base stations 402. Likewise, (macro) cells 404-1 and 404-2 are collectively referred to herein as (macro) cells 404 and individually as (macro) cells 404. The RAN may also include a plurality of low power nodes 406-1 to 406-4 that control the corresponding small cells 408-1 to 408-4. The low-power nodes 406-1 to 406-4 may be small base stations, such as pico or femto base stations, or Remote Radio Heads (RRHs), etc. It is noted that although not shown, one or more of small cells 408-1 through 408-4 may alternatively be provided by base station 402. Low-power nodes 406-1 through 406-4 are generally referred to herein collectively as low-power nodes 406 and individually as low-power nodes 406. Likewise, small cells 408-1 through 408-4 are generally referred to herein collectively as small cells 408 and individually as small cells 408. The cellular communication system 400 also includes a core network 410, referred to as a 5G core (5 GC) in 5 GS. The base station 402 (and optionally the low power node 406) is connected to a core network 410.

Base station 402 and low-power node 406 provide service to wireless communication devices 412-1 through 412-5 in corresponding cells 404 and 408. The wireless communication devices 412-1 through 412-5 are generally referred to herein collectively as wireless communication devices 412 and individually as wireless communication devices 412. In the following description, the wireless communication device 412 is typically a UE, but the invention is not limited thereto.

Downlink transmissions may be dynamically scheduled, i.e., in each slot, the gNB sends Downlink Control Information (DCI) over the PDCCH, which information relates to the UE data to be transmitted and on which RBs and OFDM symbols the data is transmitted in the current downlink slot. The PDCCH is typically transmitted in the first few OFDM symbols of each slot in the NR. UE data is carried on the PDSCH.

Three DCI formats, DCI format 1_0, DCI format 1_1, and DCI format 1_2, are defined in NR for scheduling PDSCH. DCI format 1_0 is smaller in size than DCI 1_1 and may be used when the UE is not yet connected to the network, while DCI format 1_1 may be used to schedule MIMO (multiple input multiple output) transmissions with up to 2 Transport Blocks (TBs). NR version 16 (Rel-16) has DCI format 1 _2introduced to support configurable sizes of certain bit fields in DCI.

One or more of the following bit fields may be included in the DCI: frequency Domain Resource Allocation (FDRA); time Domain Resource Allocation (TDRA); modulation and Coding Scheme (MCS); new Data Indicator (NDI); redundancy Version (RV); numbering the HARQ processes; PUCCH Resource Indicator (PRI); a PDSCH-to-HARQ _ feedback timing indicator (K1); an antenna port; and a Transport Configuration Indication (TCI).

The UE first detects and decodes the PDCCH, and if the decoding is successful, decodes the corresponding PDSCH based on the decoded DCI carried in the PDCCH. The PDSCH decoding status is sent back to the gNB in the form of HARQ acknowledgement in the PUCCH resources indicated by the PRI. An example is shown in fig. 3. The time offset T1 between the reception of DL DCI and the corresponding PDSCH is determined by the slot offset and the starting symbol of the PDSCH indicated in the TDRA in the DCI. The time offset T2 between the receipt of the DL DCI and the corresponding HARQ ack is provided by the PDSCH-to-HARQ _ feedback timing indicator in the DCI.

Time domain resource allocation

When the UE is scheduled by DCI to receive PDSCH, a Time Domain Resource (TDRA) allocation field value m of the DCI provides a row index m +1 for a time domain resource allocation table. When DCI is detected, the PDSCH time domain resource allocation is made according to the RRC-configured TDRA list listed in the RRC parameter PDSCH-timedomainallocesionlist provided in the UE-specific PDSCH configuration PDSCH-Config. Each TDRA entry in the TDRA list defines a time slot offset K between the PDSCH and the PDCCH that schedules the PDSCH ₀ A start and length indicator, SLIV, a PDSCH mapping type (type a or type B) to be assumed in PDSCH reception, and optionally a repetition number, repNumR16.

TCI State

Demodulation reference signals (DM-RS) are used for coherent demodulation of PDSCH. The DM-RS is confined in the resource blocks carrying the associated PDSCH and mapped onto the allocated Resource Elements (REs) of the OFDM time-frequency grid in the NR so that the receiver can efficiently process time/frequency selective fading radio channels. One PDSCH may have one or more DMRSs, each associated with one antenna port. An antenna port for the PDSCH is indicated in DCI scheduling the PDSCH.

Several signals may be transmitted from different antenna ports at the same location. These signals may have the same large scale properties when measured at the receiver, for example in terms of doppler shift/spread, average delay spread or average delay. These antenna ports are then referred to as quasi co-located (QCL). The network may then signal to the UE that both antenna ports are QCLs. If the UE knows that both antenna ports are QCL with respect to a particular parameter (e.g., doppler spread), the UE may estimate the parameter based on a reference signal transmitted on one transmit antenna port and use the estimate when receiving another reference signal or physical channel on the other antenna port. Typically, the first antenna port is represented by a measurement reference signal (referred to as source RS), such as a channel state information reference signal (CSI-RS), and the second antenna port is a DMRS (referred to as target RS) for PDSCH reception.

In NR, QCL relationship between demodulation reference signals (DMRS) in PDSCH and other reference signals is described by TCI state. Depending on the capability of the UE, up to 128 TCI states may be configured in frequency range 2 (FR 2) and up to 8 TCI states may be configured in FR1 for the UE through RRC signaling. Each TCI state contains QCL information for purposes of PDSCH reception. In DCI scheduling PDSCH, one or two TCI states may be dynamically signaled to the UE in the TCI field.

The QCL relationship between DMRS and other reference signals in PDCCH is described by TCI status of control resource set (CORESET) transmitting PDCCH. For each CORESET configured to the UE, the TCI state list is RRC configured; one of which is activated by the MAC CE. In NR Rel-15, a maximum of three CORESET per bandwidth part (BWP) may be configured for the UE. In NR Rel-16, up to five CORESET per BWP may be configured for the UE, depending on the capabilities.

PDSCH transmission over multiple transmission points or panels (TRP)

In one scenario, downlink data is sent over multiple TRPs, with different MIMO layers sent over different TRPs. This is called non-coherent joint transmission (NC-JT). In another scenario, different time/frequency resources may be allocated to different TRPs and one or more PDSCHs may be transmitted through different TRPs. Two ways of scheduling multiple TRP transmissions are specified in NR Rel-16: multiple TRP transmissions based on multiple PDCCHs and multiple TRP transmissions based on a single PDCCH. Multiple TRP transmissions based on multiple PDCCHs and multiple TRP transmissions based on a single PDCCH may be used to serve downlink eMBB traffic as well as downlink URLLC traffic to a UE.

Multi-PDCCH based DL data transmission through multiple transmission points (TRPs)

An example is shown in fig. 5, where data is sent to the UE through two TRPs, each carrying one TB mapped to one codeword. When the UE has four reception antennas and only two transmission antennas per TRP, the UE can support four MIMO layers at the maximum, but can transmit two MIMO layers at the maximum per TRP. In this case, by sending data to the UE on two TRPs, the peak data rate to the UE may be increased, since up to four aggregation layers from two TRPs may be used. This is beneficial when the traffic load and resource utilization in each TRP is low. In this example, a single scheduler is used to schedule data on two TRPs. One PDCCH is transmitted from each of two TRPs in a slot, one PDSCH being scheduled each. This is referred to as a multiple PDCCH or multiple DCI scheme, where the UE receives two PDCCHs and associated two PDSCHs from two TRPs in a slot.

In the NR specification, 3GPP TS 38.211, there is a restriction specification:

"the UE may assume PDSCH DM-RS within the same CDM group is quasi co-located in terms of doppler shift, doppler spread, average delay, delay spread, and spatial Rx. "

In the case where one UE is not scheduled to all DMRS ports in one CDM group, there may be a possibility to simultaneously schedule another UE using the remaining ports of that CDM group. The UE may then estimate the channel (and thus the interfering signal) of the other UE in order to perform coherent interference suppression. This is therefore useful in MU-MIMO scheduling and UE interference suppression.

In the case of a multi-TRP scenario, where the UE receives PDSCH via multiple PDCCHs transmitted from different TRPs, the signals transmitted from the different TRPs are likely not quasi co-located because the TRPs may be spatially separated. In this case, the PDSCH transmitted from different TRPs will have different TCI states associated therewith. Furthermore, according to the above-described limitation of 3gpp TS 38.211, the two PDSCH DM-RSs associated with two TRPs must belong to different DM-RS CDM groups (since they are not QCLs, they cannot belong to the same DM-RS CDM group). Fig. 6 shows an example relationship between TCI status and DM-RS CDM group for multiple PDCCH multiple TRP scenarios. In this example, PDSCH1 is associated with TCI state p, while PDSCH2 is associated with TCI state q. PDSCH DM-RS from different TRPs also belong to different DM-RS CDM groups because they are not quasi co-located. In this example, the DMRS of PDSCH1 belongs to CDM group u, and the DMRS of PDSCH2 belongs to CDM group v.

Single PDCCH based DL data transmission through multiple transmission points (TRPs)

The PDSCH may be transmitted from multiple TRPs to the UE. The propagation channels may be different, since different TRPs may be located at different physical locations and/or have different beams. To facilitate receiving PDSCH data from different TRPs or beams, a UE may be indicated by a single code point of a TCI field in DCI with two TCI states, each TCI state associated with a TRP or beam.

Fig. 7 illustrates one example of PDSCH transmission over two TRPs using a single DCI, where different layers of the PDSCH with a single codeword (e.g., CW 0) are transmitted over the two TRPs, each TRP associated with a different TCI state. In this case, two DMRS ports (one per layer) in two CDM groups are also signaled to the UE. The first TCI state is associated with DMRS ports in the first CDM group, and the second TCI state is associated with DMRS ports in the second CDM group. This method is commonly referred to as NC-JT (non-coherent joint transmission) or scheme 1a in the NR Rel-163GPP discussion.

Transmitting PDSCH through multiple TRPs may also be used to improve PDSCH transmission reliability for URLLC applications. A number of methods have been introduced in NR Rel-16, including "FDM scheme a", "FDM scheme B", "TDM scheme a", and slot-based TDM scheme. Note that the term scheme 4 is used in the discussion of NR Rel-163GPP that relates to a slot-based TDM scheme.

Fig. 8 shows an example of multi-TRP PDSCH transmission using FDM scheme a, in which PDSCH is transmitted through TRP1 in PRG (pre-coded RB group) {0,2,4} and TRP2 in PRG {1,3,5 }. Transmissions from TRP1 are associated with TCI state 1 and transmissions from TRP2 are associated with TCI state 2. Since the transmissions from TRP1 and TRP2 do not overlap in the case of FDM scheme a, the DMRS ports may be the same (i.e., DMRS port 0 is used for both transmissions). The PDSCH is scheduled by the PDCCH transmitted through the TRP 1.

Fig. 9 shows an example data transmission using FDM scheme B, where PDSCH #1 is transmitted in PRG {0,2,4} from TRP1, and PDSCH #2 having the same TB is transmitted in PRG {1,3,5} from TRP 2. Transmissions from TRP1 are associated with TCI state 1 and transmissions from TRP2 are associated with TCI state 2. Since transmissions from TRP1 and TRP2 do not overlap in the case of FDM scheme B, DMRS ports may be the same (i.e., DMRS port 0 is used for both transmissions). The two PDSCHs carry the same coded data payload but with the same or different redundancy versions so that the UE can soft combine the two PDSCHs for more reliable reception.

Fig. 10 shows an example data transmission using TDM scheme a, where PDSCH repetition occurs in a small slot of four OFDM symbols within the slot. Each PDSCH may be associated with the same or different RV. PDSCH #1 transmissions from TRPl are associated with a first TCI state and PDSCH #2 transmissions from TRP2 are associated with a second TCI state.

An example of multi-TRP data transmission using a TDM scheme based on a slot is shown in fig. 11, in which four PDSCHs of the same TB are transmitted through two TRPs and in four consecutive slots. Each PDSCH is associated with a different RV. Transmissions of odd PDSCHs from TRP1 are associated with a first TCI state and transmissions of even PDSCHs from TRP2 are associated with a second TCI state.

For all single PDCCH based DL multi-TRP PDSCH schemes, a single DCI transmitted from one TRP is used to schedule multiple PDSCH transmissions through the TRP. The network configures the UE with multiple TCI states via RRC and introduces a new MAC CE in NR Rel-16. This MAC CE may be used to map code points in the TCI field to one or two TCI states.

Default TCI State

Single TRP transmission

If no TCI code points map to two different TCI states and the time offset between the received DL DCI and the corresponding PDSCH is less than the higher layer configured threshold timedurationformqcl, instead of using the TCI state indicated in the TCI field in the DCI scheduling the PDSCH, the UE may assume that the TCI state of the PDSCH is given by the TCI state activated by the CORESET with the lowest ControlResourceSetId id in the one or more CORESETs in the latest slot in the active BWP of the serving cell monitored for the UE. The TCI state is referred to herein as a default TCI state. If none of the TCI states configured for the serving cell of the scheduled PDSCH contains 'QCL-type', the UE should acquire other QCL hypotheses from the TCI state indicated by the PDSCH for which the DCI is scheduled, regardless of the time offset between the reception of the DL DCI and the corresponding PDSCH.

Multiple TRP transmission

If the offset between the reception of the DL DCI and the corresponding PDSCH is less than the threshold timedurationformqcl, and the TCI state of the at least one configuration of the serving cell for the scheduled PDSCH contains 'QCL-TypeD', and the at least one TCI codepoint configures two TCI states, the UE may assume that the TCI state of the PDSCH is given by the TCI state corresponding to the lowest codepoint of the TCI codepoints containing two different TCI states. In this case, the two TCI states are the default TCI states.

The default TCI state corresponds to the Rx beam used by the UE for receiving (and buffering) the PDSCH before the corresponding DCI is decoded (since the UE does not know what TCI state is needed to receive the PDSCH before DCI decoding otherwise, if the time offset between DCI and PDSCH (unknown before DCI is decoded) is below a threshold, the wrong Rx beam may be used and the PDSCH may be lost.

Channel state information reference signal (CSI-RS)

For CSI measurement and feedback, a CSI-RS is defined. The CSI-RS is transmitted on each transmit antenna (or antenna port) and is used by the UE to measure downlink channels between each transmit antenna port and each receive antenna. The antenna ports are also referred to as CSI-RS ports. The number of antenna ports supported in NR is {1,2,4,8, 12, 16, 24, 32}. By measuring the received CSI-RS, the UE can estimate the channel that the CSI-RS is traversing, including the radio propagation channel and antenna gain. The CSI-RS used for the above purpose is also referred to as a non-zero power (NZP) CSI-RS.

The NZP CSI-RS may be configured to be transmitted in one slot and some REs in some slots. Fig. 12 shows an example of CSI-RS REs for 12 antenna ports, where 1 RE per RB per port is shown.

Also, a CSI interference measurement resource (CSI-IM) is defined in the NR for the UE to measure interference. One CSI-IM resource contains four REs, or four adjacent REs in frequency in the same OFDM symbol, or 2 × 2 adjacent REs in both time and frequency in one slot. By measuring the NZP CSI-RS based channel and the CSI-IM based interference, the UE can estimate the effective channel and noise plus interference to determine the CSI, i.e. rank, precoding matrix and channel quality.

In the NR, the CSI-RS may be aperiodic, semi-persistent, and periodic. Aperiodic CSI-RS transmission is typically triggered by UL DCI (i.e., DCI format 01 and DCI format 02).

CSI framework in NR

In the NR, the UE may be configured with a plurality of CSI report settings (each represented by a higher layer parameter CSI-ReportConfig with an associated identification ReportConfigID) and a plurality of CSI resource settings (each represented by a higher layer parameter CSI-resourceconconfig with an associated identification CSI-resourceconconfigid). Each CSI resource set may contain a plurality of sets of CSI resources (each represented by a higher layer parameter NZP-CSI-RS-resource set with an associated identification NZP-CSIRS-resource for channel measurement or by a higher layer parameter CSI-IM-resource set with an associated identification CSI-IM-resource for interference measurement), and each set of NZP CSI-RS resources for channel measurement may contain up to 8 NZP CSI-RS resources. For each CSI reporting setting, the UE feeds back a set of CSI, which may include one or more of a CSI-RS resource indicator (CRI), RI, PMI, and CQI per CW, depending on the configured number of reports.

In each CSI reporting setting, it contains one or more of the following information:

CSI resource setting for channel measurement based on NZP CSI-RS resource (denoted by higher layer parameter resourcesForChannelMeasurement)

CSI-resource setting for interference measurement based on CSI-IM resources (denoted by higher layer parameters CSI-IM-resources ForInterference)

Optionally, CSI resource setting for interference measurement based on NZP CSI-RS resources (represented by higher layer parameter NZP-CSI-RS-resources for interference)

Time domain behavior, i.e. periodic, semi-persistent or aperiodic reporting (represented by the higher layer parameter reportConfigType)

Frequency granularity, i.e. wideband or subband

CSI parameters (such as RI, PMI, CQI, L1-RSRP/L1_ SINR and CRI) to be reported in case of multiple NZP CSI-RS resources in one resource set are used for channel measurement (represented by higher layer parameters reportQuantity, such as 'CRI-RI-PMI-CQI', 'CRI-RSRP' or 'ssb-Index-RSRP')

Codebook type, i.e. type I or II in case of reporting, and codebook subset restriction

Measurement limits

For periodic and semi-static CSI reporting, only one set of NZP CSI-RS resources may be configured for channel measurements and one set of CSI-IM resources for interference measurements. For aperiodic CSI reporting, the CSI resource setup for channel measurement may contain more than one set of NZP CSI-RS resources for channel measurement. If the CSI resource setting for channel measurement contains multiple NZP CSI-RS resource sets for aperiodic CSI reporting, only one NZP CSI-RS resource set may be selected and indicated to the UE. For aperiodic CSI reporting, a status list (given by the higher layer parameter CSI-AperiodicTriggerStateList) is triggered. Each trigger state in the CSI-AperiodicTriggerStateList contains an associated CSI-reportconfigurations list indicating the channel and (optionally) interfering resource set ID. For a UE configured with a higher layer parameter CSI-aperiodictriggerstatistist, if a resource setting linked to a CSI-ReportConfig has multiple aperiodic resource sets, only one aperiodic CSI-RS resource set from the resource setting in an aperiodic CSI-RS resource set is associated with a trigger state, and the UE is per trigger state per resource setting of the higher layer configuration to select one NZP CSI-RS resource set from the resource setting.

When more than one NZP CSI-RS resource is contained in the selected set of NZP CSI-RS resources for channel measurement, the UE reports a CSI-RS resource indicator (CRI) to indicate to the gNB the selected one of the resource sets, along with the RI, PMI and CQI associated with the selected NZP CSI-RS resource. This type of CSI assumes that the PDSCH is transmitted from a single Transmission Reception Point (TRP), and the CSI is also referred to as single TRP CSI.

Existing NR UE behavior when aperiodic CSI-RS collides with PDSCH

When aperiodic CSI-RS and PDSCH collision is involved, the following UE behavior is specified in the existing NR specification in TS 38.214:

if the scheduling offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resource is less than the UE reported threshold beamSwitchTiming defined in [ TS 38.306 ]:

if there is a PDSCH with an indicated TCI state in the same symbol as the CSI-RS, where the PDSCH is scheduled with a scheduling offset greater than or equal to the threshold timedurationformqcl, the UE also applies the QCL assumption for the PDSCH when receiving the aperiodic CSI-RS.

Otherwise, when receiving the aperiodic CSI-RS, the UE applies a QCL hypothesis for CORESET associated with the monitored search space with the lowest controlResourceSetId in the most recent slot, where one or more CORESETs in the active BWP of the serving cell are monitored.

Certain challenges currently exist. The existing NR standard defines UE behavior when the PDSCH is indicated in a single TCI state when the aperiodic CSI-RS collides with the PDSCH. There is no definition in the current NR specification of how the UE behaves (i.e., what QCL assumption the UE makes) to receive the aperiodic CSI-RS when it collides with the PDSCH indicated with two TCI states in the DCI, which is a pending problem that needs to be solved. In particular, this UE behavior when PDSCH uses one of the following schemes is not defined: a single PDCCH based NC-JT scheme; "FDM scheme a"; "FDM scheme B"; "TDM scheme A".

Systems and methods are provided for determining a Transmission Configuration Indication (TCI) state of an Aperiodic (AP) channel state information reference signal (CSI-RS) overlapping a Physical Downlink Shared Channel (PDSCH) transmission. In some embodiments, a method performed by a wireless device for determining a TCI state for receiving one or more AP CSI-RSs comprises one or more of: receiving one or more AP CSI-RSs in the same symbol as a downlink transmission scheduled by a DCI having two TCI states indicated in the DCI; receiving a trigger for one or more AP CSI-RS with a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource, wherein the scheduling offset is less than a threshold reported by a wireless device; and determining that the downlink transmission is scheduled according to one of the group consisting of: "TDM scheme A"; "FDM scheme a"; "FDM scheme B"; and schemes in which different layer sets of downlink transmissions are received in different TCI states. In some embodiments, the wireless device applies QCL assumptions on PDSCH transmission occasions when receiving AP CSI-RS, as appropriate.

Fig. 13 illustrates a method performed by a wireless device for determining a TCI status for receiving one or more AP CSI-RSs. In some embodiments, the wireless device performs one or more of: receiving one or more AP CSI-RSs in the same symbol as a downlink transmission scheduled by the DCI with two TCI states indicated in the DCI (step 1300); receiving a trigger for one or more AP CSI-RS with a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource, wherein the scheduling offset is less than a threshold reported by a wireless device (step 1302); and determining that the downlink transmission is scheduled according to one of the group consisting of: "TDM scheme A"; "FDM scheme a"; "FDM scheme B"; and schemes in which different layer sets of downlink transmissions are received in different TCI states (step 1304). In some embodiments, the wireless device applies QCL assumptions on PDSCH transmission occasions when receiving AP CSI-RS, as appropriate (step 1306). In some embodiments, this defines the UE behavior (i.e., what QCL assumption the UE makes) of receiving aperiodic CSI-RS when it collides with PDSCH when PDSCH is indicated in two TCI states. One benefit is that the proposed solution defines which QCL properties should be used to receive conflicting aperiodic CSI-RS, which was not previously defined in NR. With the proposed solution, aperiodic CSI-RS can be flexibly triggered in overlapping symbols, where PDSCH is scheduled according to one of NC-JT scheme "FDM scheme a", "FDM scheme B", and "TDM scheme a" based on a single PDCCH.

Fig. 14 illustrates a method performed by a base station for indicating a TCI status for receiving one or more AP CSI-RSs. In some embodiments, the base station performs one or more of: transmitting one or more AP CSI-RSs to the wireless device in the same symbol as a downlink transmission scheduled by the DCI with two TCI states indicated in the DCI (step 1400); triggering one or more AP CSI-RS with a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource, wherein the scheduling offset is less than a threshold reported by the wireless device (step 1402); and scheduling downlink transmissions according to one of the group consisting of: "TDM scheme A"; "FDM scenario a"; "FDM scheme B"; and a scheme in which different layer sets of downlink transmissions are received in different TCI states (step 1404). In some embodiments, the base station assumes that the wireless device applies QCL assumptions on PDSCH transmission occasions when receiving AP CSI-RS, depending on the surrounding environment (step 1406). In some embodiments, this defines the UE behavior (i.e., what QCL assumption the UE makes) of receiving aperiodic CSI-RS when it collides with PDSCH when PDSCH is indicated in two TCI states. One benefit is that the proposed solution defines which QCL properties should be used to receive conflicting aperiodic CSI-RS, which was not previously defined in NR. With the proposed solution, aperiodic CSI-RS can be flexibly triggered in overlapping symbols, where PDSCH is scheduled according to one of single PDCCH based NC-JT scheme "FDM scheme a", "FDM scheme B", and "TDM scheme a".

Embodiment 1 is directed to a scenario when AP CSI-RS collides with PDSCH scheduled according to "TDM scheme a" and the scheduling offset is above a threshold.

In this embodiment, the UE is configured to receive PDSCH according to "TDM scheme a" and is indicated with two TCI statuses in the DCI, where the first indication TCI status applies to PDSCH transmission occasion 1 (denoted PDSCH 1) and the second indication TCI status applies to PDSCH transmission occasion 2 (denoted PDSCH 2). This corresponds to the case where the scheduling offset from the last symbol of the PDCCH carrying the DCI to the first symbol of PDSCH1 is greater than or equal to the threshold timeduration format qcl.

Furthermore, in this embodiment, aperiodic CSI-RS (AP CSI-RS) is triggered to the UE by another DCI with a scheduling offset between the last symbol of the PDCCH carrying the triggered DCI (i.e., the DCI triggering the AP CSI-RS) and the first symbol of the aperiodic CSI-RS resource, which is less than the threshold beamswitch timing reported by the UE. In this case, there are two possibilities as shown in fig. 15, fig. 15 showing a first example of embodiment 1 considering collision of AP CSI-RS with PDSCH scheduled according to the "TDM scheme a".

As shown in fig. 15 (a), when the AP CSI-RS is in the same symbol as PDSCH1, the UE applies the QCL assumption of PDSCH1 (given by the first indication TCI state in DCI) when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as used for receiving PDSCH1, the spatial QCL property of PDSCH1 being given by the first indication TCI status in the DCI.

As shown in fig. 15 (B), when the AP CSI-RS is in the same symbol as PDSCH2, the UE applies the QCL assumption of PDSCH2 (given by the second indication TCI state in DCI) when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as used for receiving PDSCH2, the spatial QCL property of PDSCH2 being given by the second indication TCI status in DCI.

There is also a third possibility as shown in fig. 16, which shows a second example of embodiment 1 considering collision of AP CSI-RS with PDSCH scheduled according to "TDM scheme 4". As shown in the figure, in this third possibility, the AP CSI-RS overlaps with the symbols of both PDSCH1 and PDSCH2. In this case, since the CSI-RS of a single AP CSI-RS resource is transmitted from one TRP, it is impossible to receive the CSI-RS of the single AP CSI-RS resource using two different QCL hypotheses, which the UE considers to be an error case and discards the AP CSI-RS (i.e., does not receive the AP CSI-RS).

Embodiment 2 is directed to a scenario when the AP CSI-RS collides with PDSCH scheduled according to "TDM scheme a" and one scheduling offset is below a threshold.

In this embodiment, the UE is configured to receive PDSCH according to "TDM scheme a" and is indicated with 2 TCI statuses in DCI. In this case, the scheduling offset from the last symbol of PDCCH to the first symbol of PDSCH1 is less than the threshold timeduration format qcl, but the scheduling offset from the last symbol of PDCCH to the first symbol of PDSCH2 is greater than or equal to the threshold. In this case, a first default TCI state is applied to the PDSCH1, and a second indication TCI state is applied to the PDSCH2. According to the NR Rel-16 specification, the default TCI state for PDSCH is given by the TCI state corresponding to the lowest of the TCI codepoints containing two different TCI states. Thus, a first default TCI state is defined as the first of two different TCI states corresponding to the lowest such codepoint.

Further, in this embodiment, aperiodic CSI-RS (AP CSI-RS) is triggered to the UE by another DCI with a scheduling offset between the last symbol of the PDCCH carrying the triggered DCI and the first symbol of the aperiodic CSI-RS resource, which is less than a threshold, such as the UE reported threshold beamswitch timing. In this case, there are two possibilities as shown in fig. 17, fig. 17 showing a first example of embodiment 2 considering the collision of AP CSI-RS with PDSCH scheduled according to the "TDM scheme a".

As shown in (a) of fig. 17, when the AP CSI-RS is in the same symbol as the PDSCH1, the UE applies the QCL assumption (given by the first default TCI state) of the PDSCH1 when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as used for receiving PDSCH1, the spatial QCL property of PDSCH1 being given by the first default TCI state.

As shown in fig. 17 (B), when the AP CSI-RS is in the same symbol as PDSCH2, the UE applies the QCL assumption (given by the second indication TCI state in DCI) of PDSCH2 when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as used for receiving PDSCH2, the spatial QCL property of PDSCH2 being given by the second indication TCI status in DCI.

There is also a third possibility as shown in fig. 18, which shows a second example of embodiment 2 that considers collision of AP CSI-RS with PDSCH scheduled according to "TDM scheme a". As shown, in this third possibility, the AP CSI-RS overlaps between symbols of both PDSCH1 and PDSCH2. In this case, the UE drops (i.e., does not receive) the AP CSI-RS since it is not possible to receive different CSI-RS for a single AP CSI-RS resource using two different QCL hypotheses.

Embodiment 3 is directed to a scenario when the AP CSI-RS collides with the PDSCH scheduled according to the "TDM scheme a" and both scheduling offsets are below a threshold.

In the present embodiment, the UE is configured to receive PDSCH according to "TDM scheme a" and indicated with two TCI statuses in DCI. In this case, a scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH1 is less than a threshold timeduration formqcl, and/or a scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH2 is less than the threshold timeduration formqcl.

In this case, a first default TCI state is applied to PDSCH1, and a second default TCI state is applied to PDSCH2. According to the NR Rel-16 specification, the default TCI state for PDSCH is given by the TCI state corresponding to the lowest of the TCI codepoints containing two different TCI states. Thus, the first default TCI state and the second default TCI state correspond to the first and second of two different TCI states, respectively, corresponding to the lowest such codepoints.

Further, in this embodiment, an aperiodic CSI-RS (AP CSI-RS) is triggered to the UE, where the scheduling offset between the last symbol of the PDCCH carrying the triggered DCI and the first symbol of the aperiodic CSI-RS resource is less than the UE reporting threshold beamSwitchTiming. In this case, there are two possibilities as shown in fig. 19, which shows a first example of embodiment 3 considering the collision of the AP CSI-RS with the PDSCH scheduled according to the "TDM scheme a".

As shown in fig. 19 (a), when the AP CSI-RS is in the same symbol as the PDSCH1, the UE applies the QCL assumption (given by the first default TCI state) of the PDSCH1 when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as used for receiving PDSCH1, the spatial QCL property of PDSCH1 being given by the first default TCI state.

As shown in fig. 19 (B), when the AP CSI-RS is in the same symbol as the PDSCH2, the UE applies the QCL assumption (given by the second default TCI state) of the PDSCH2 when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as used for receiving PDSCH2, the spatial QCL property of PDSCH2 being given by the second default TCI state.

There is also a third possibility as shown in fig. 20, which shows a second example of embodiment 3 that considers collision of AP CSI-RS with PDSCH scheduled according to "TDM scheme a". As shown, in this third possibility, the AP CSI-RS overlaps between symbols of both PDSCH1 and PDSCH2. In this case, the UE discards the AP CSI-RS (i.e., does not receive the AP CSI-RS) since it is not possible to receive different CSI-RS of a single AP CSI-RS resource using two different QCL hypotheses.

Embodiment 4 is directed to a scenario when an AP CSI-RS collides with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme and a scheduling offset is above a threshold.

In this embodiment, the UE is configured to receive the PDSCH according to a single PDCCH-based NC-JT scheme and is indicated in the DCI with two TCI states, where the two indicated TCI states are for receiving different layer sets corresponding to the PDSCH (i.e., a first layer set corresponding to a first TCI state and a second layer set corresponding to a second TCI state). This corresponds to a case where a scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH is greater than or equal to a threshold timeduration formqcl.

Further, in one case, an aperiodic CSI-RS (APCSI-RS) is triggered to the UE by another DCI, where a scheduling offset between the last symbol of the PDCCH carrying the triggered DCI and the first symbol of the aperiodic CSI-RS resource is less than a threshold beamSwitchTiming reported by the UE. Fig. 21 shows a first example of embodiment 4 considering collision of an AP CSI-RS with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme, where a first TCI state is assumed for the AP CSI-RS. The aperiodic CSI-RS overlaps with the PDSCH symbols as shown in fig. 21.

In this case, when the AP CSI-RS is in the same symbol as the PDSCH, as shown in fig. 21, the UE applies the QCL hypothesis given by the first indication TCI state in the DCI for the PDSCH when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as used for receiving the PDSCH, whose spatial QCL properties are given by the first indication TCI status in the DCI.

In the second case, two AP CSI-RSs are triggered to the UE (e.g., each AP CSI-RS sent from a different TRP), where the scheduling offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resource is less than the threshold beamswitch timing reported by the UE. Fig. 22 shows a second example of embodiment 4 considering collision of AP CSI-RS with PDSCH scheduled according to single PDCCH-based NC-JT scheme, where first and second TCI states are assumed for the first and second AP CSI-RS, respectively. The two aperiodic CSI-RS overlap with PDSCH symbols as shown in fig. 22.

In this case, for the first AP CSI-RS, the UE applies the QCL hypothesis given by the first indication TCI status in the DCI for the PDSCH when receiving the first AP CSI-RS. In other words, the UE receives the first AP CSI-RS using the same receive beam as used for receiving the PDSCH, whose spatial QCL property is given by the first indication TCI status in the DCI.

For the second AP CSI-RS, the UE applies the QCL assumption given by the second indication TCI status in the DCI for the PDSCH when receiving the second AP CSI-RS. In other words, the UE receives the second AP CSI-RS using the same receive beam as used for receiving the PDSCH, whose spatial QCL property is given by the second indication TCI status in the DCI.

The first AP CSI-RS resource and the second AP CSI-RS resource are defined by using a CSI-RS resource ID or a CSI-RS resource set ID (namely NZP-CSI-RS-ResourceSetld) to which the AP CSI-RS resource belongs. For example, if two AP CSI-RS resources are in different CSI-RS resource set IDs, the AP CSI-RS resource with the smallest NZP-CSI-RS-ResourceSetId is the first AP CSI-RS resource and the AP CSI-RS resource with the largest NZP-CSI-RS-ResourceSetId is the second AP CSI-RS resource. Similar definitions of the first AP CSI-RS resource and the second AP CSI-RS resource may be achieved by using a CSI-RS resource ID instead of a CSI-RS resource set ID.

Although the present embodiment is written from the perspective of a PDSCH scheduled according to a single PDCCH-based NC-JT scheme, it can be easily extended to a PDSCH scheduled via the "FDM scheme a" or the "FDM scheme B".

Embodiment 5 is directed to a scenario when an AP CSI-RS collides with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme and a scheduling offset is below a threshold.

In the present embodiment, the UE is configured to receive the PDSCH according to a single PDCCH-based NC-JT scheme and is indicated in the DCI with 2 TCI states, wherein 2 default TCI states are used to receive different layers corresponding to the PDSCH. This corresponds to a case where a scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH is less than a threshold timeduration format qcl. According to the NR Rel-16 specification, the default TCI state for PDSCH is given by the TCI state corresponding to the lowest of the TCI codepoints containing two different TCI states.

Further, in one case, an aperiodic CSI-RS (AP CSI-RS) is triggered to the UE, where the scheduling offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resource is less than the threshold beamswitch timing reported by the UE. Fig. 23 shows a first example of embodiment 5 considering collision of an AP CSI-RS with a PDSCH scheduled according to a single PDCCH-based NC-JT scheme, wherein a first default TCI state is assumed for the AP CSI-RS. The aperiodic CSI-RS overlaps the PDSCH symbols as shown in fig. 23.

In this case, when the AP CSI-RS is in the same symbol as the PDSCH, as shown in fig. 23, the UE applies the QCL assumption given by the first default TCI state in the DCI for the PDSCH when receiving the AP CSI-RS. In other words, the UE receives the AP CSI-RS using the same receive beam as used for receiving the PDSCH, whose spatial QCL properties are given by the first default TCI state.

In the second case, two AP CSI-RSs are triggered to the UE (e.g., each AP CSI-RS sent from a different TRP), where the scheduling offset between the last symbol of the PDCCH carrying the triggering DCI and the first symbol of the aperiodic CSI-RS resource is less than the threshold beamswitch timing reported by the UE. Fig. 24 shows a second example of embodiment 5 considering collision of AP CSI-RS with PDSCH scheduled according to a single PDCCH-based NC-JT scheme, where first and second default TCI states are assumed for the first and second AP CSI-RS, respectively. The two aperiodic CSI-RS overlap with the PDSCH symbols as shown in fig. 24.

In this case, for the first AP CSI-RS, the UE applies the QCL assumption given by the first default TCI state for the PDSCH when receiving the first AP CSI-RS. In other words, the UE receives the first AP CSI-RS using the same receive beam as used for receiving the PDSCH, whose spatial QCL properties are given by the first default TCI state in the DCI.

For the second AP CSI-RS, the UE applies the QCL assumption given by the second default TCI state for the PDSCH when receiving the second AP CSI-RS. In other words, the UE receives the second AP CSI-RS using the same receive beam as used for receiving the PDSCH, whose spatial QCL property is given by the second indication TCI status in the DCI.

The first AP CSI-RS resource and the second AP CSI-RS resource are defined using a CSI-RS resource ID or a CSI-RS resource set ID (i.e., NZP-CSI-RS-ResourceSetId) to which the AP CSI-RS resource belongs. For example, if two AP CSI-RS resources are in different CSI-RS resource set IDs, the AP CSI-RS resource with the smallest NZP-CSI-RS-ResourceSetId is the first AP CSI-RS resource and the AP CSI-RS resource with the largest NZP-CSI-RS-ResourceSetId is the second AP CSI-RS resource. Similar definitions of the first AP CSI-RS resource and the second AP CSI-RS resource may be achieved by using a CSI-RS resource ID instead of a CSI-RS resource set ID.

Although the present embodiment is written from the perspective of a PDSCH scheduled according to a single PDCCH-based NC-JT scheme, it can be easily extended to a PDSCH scheduled via "FDM scheme a" or "FDM scheme B".

Fig. 25 is a schematic block diagram of a radio access node 2500 in accordance with some embodiments of the present invention. Optional functions are represented by dashed boxes. Radio access node 2500 may be, for example, base station 402 or 406 or a network node that implements all or part of the functionality of base station 402 or a gNB described herein. As shown, the radio access node 2500 includes a control system 2502 that includes one or more processors 2504 (e.g., central Processing Units (CPUs), application Specific Integrated Circuits (ASICs), field Programmable Gate Arrays (FPGAs), etc.), memory 2506, and a network interface 2508. The one or more processors 2504 are also referred to herein as processing circuits. Further, radio access node 2500 may include one or more radio units 2510, each radio unit 2510 including one or more transmitters 2512 and one or more receivers 2514 coupled to one or more antennas 2516. The radio unit 2510 may be referred to as or be part of a radio interface circuit. In some embodiments, the radio 2510 is external to the control system 2502 and connected to the control system 2502 via, for example, a wired connection (e.g., an optical cable). However, in some other embodiments, the radio 2510 and possibly the antenna 2516 are integrated with the control system 2502. The one or more processors 2504 operate to provide one or more functions of the radio access node 2500, as described herein. In some embodiments, the functions are implemented in software that is stored in, for example, the memory 2506 and executed by the one or more processors 2504.

Fig. 26 is a schematic block diagram illustrating a virtualized embodiment of a radio access node 2500 in accordance with some embodiments of the present invention. The discussion is equally applicable to other types of network nodes. In addition, other types of network nodes may have similar virtualization architectures. Again, optional functions are represented by dashed boxes.

As used herein, a "virtualized" radio access node is an implementation of the radio access node 2500 in which at least a portion of the functionality of the radio access node 2500 is implemented as a virtual component (e.g., via a virtual machine executing on a physical processing node in a network). As shown, in this example, radio access node 2500 may include a control system 2502 and/or one or more radio units 2510, as described above. Control system 2502 may be connected to radio 2510 via, for example, an optical cable or the like. Radio access node 2500 includes one or more processing nodes 2600 that are coupled to or included as part of network 2602. Control system 2502 or radio, if present, is connected to processing node 2600 via network 2602. Each processing node 2600 includes one or more processors 2604 (e.g., CPUs, ASICs, FPGAs, etc.), memory 2606, and a network interface 2608.

In this example, the functionality 2610 of the radio access node 2500 described herein is implemented at the one or more processing nodes 2600 or distributed in any desired manner among the one or more processing nodes 2600 and the control system 2502 and/or radio unit 2510. In some particular embodiments, some or all of the functionality 2610 of the radio access node 2500 described herein is implemented as virtual components executed by one or more virtual machines implemented in a virtual environment hosted by the processing node 2600. As will be appreciated by those of ordinary skill in the art, additional signaling or communication between the processing node 2600 and the control system 2502 is used to perform at least some of the desired functions 2610. It is noted that in some embodiments, control system 2502 may not be included, in which case radio 2510 communicates directly with processing node 2600 via an appropriate network interface.

In some embodiments, a computer program comprising instructions, which when executed by at least one processor, causes the at least one processor to perform the functions of the radio access node 2500 or provide a node (e.g., processing node 2600) that implements one or more of the functions 2610 of the radio access node 2500 in a virtual environment according to any embodiment described herein. In some embodiments, a carrier comprising the computer program product described above is provided. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as a memory).

Fig. 27 is a schematic block diagram of a radio access node 2500 according to some other embodiments of the present invention. Radio access node 2500 includes one or more modules 2700, each of which is implemented in software. Module 2700 provides the functionality of radio access node 2500 described herein. The discussion applies equally to processing node 2600 of fig. 26, where module 2700 can be implemented at one of processing nodes 2600 or distributed across multiple processing nodes 2600 and/or across processing node 2600 and control system 2502.

Fig. 28 is a schematic block diagram of a wireless communication device 2800 according to some embodiments of the present invention. As shown, the wireless communication device 2800 includes one or more processors 2802 (e.g., CPUs, ASICs, FPGAs, etc.), a memory 2804, and one or more transceivers 2806, each of which includes one or more transmitters 2808 and one or more receivers 2810 coupled to one or more antennas 2812. The transceiver 2806 includes radio front end circuitry connected to the antenna 2812 that is configured to condition signals communicated between the antenna 2812 and the processor 2802, as will be understood by those of ordinary skill in the art. The processor 2802 is also referred to herein as a processing circuit. The transceiver 2806 is also referred to herein as a radio circuit. In some embodiments, the functionality of the wireless communication device 2800 described above may be implemented in whole or in part in software, for example, stored in memory 2804 and executed by processor 2802. Note that the wireless communication device 2800 can include additional components not shown in fig. 28, such as, for example, one or more user interface components (e.g., including a display, buttons, a touch screen, a microphone, a speaker, etc., and/or any other components for allowing information to be input to the wireless communication device 2800 and/or for allowing information to be output from the wireless communication device 2800), a power source (e.g., a battery and associated power circuitry), and so forth.

In some embodiments, a computer program is provided that includes instructions, which when executed by at least one processor, cause the at least one processor to perform the functions of the wireless communication device 2800 according to any embodiment described herein. In some embodiments, a carrier is provided that includes the computer program product described above. The carrier is one of an electronic signal, an optical signal, a radio signal, or a computer readable storage medium (e.g., a non-transitory computer readable medium such as a memory).

Fig. 29 is a schematic block diagram of a wireless communication device 2800 according to some other embodiments of the present invention. Wireless communication device 2800 includes one or more modules 2900, each implemented in software. Module 2900 provides functionality for wireless communication device 2800 as described herein.

Referring to fig. 30, according to one embodiment, a communication system includes a telecommunications network 3000, such as a 3 GPP-type cellular network, which includes an access network 3002, such as a RAN, and a core network 3004. The access network 3002 includes a plurality of base stations 3006A, 3006B, 3006C, such as node bs, enbs, gnbs, or other types of wireless Access Points (APs), each defining a corresponding coverage area 3008A, 3008B, 3008C. Each base station 3006A, 3006B, 3006C may be connected to the core network 3004 by a wired or wireless connection 3010. A first UE3012 located in coverage area 3008C is configured to wirelessly connect to or be paged by a corresponding base station 3006C. A second UE 3014 in coverage area 3008A may be wirelessly connected to a corresponding base station 3006A. Although multiple UEs 3012, 3014 are shown in this example, the disclosed embodiments are equally applicable to the case where a single UE is in the coverage area or where a single UE is connected to a corresponding base station 3006.

The telecommunications network 3000 is itself connected to a host computer 3016, which may be embodied in hardware and/or software of a standalone server, a cloud-implemented server, a distributed server, or as a processing resource in a server farm. The host computer 3016 may be under the ownership or control of the service provider, or may be operated by or on behalf of the service provider. Connections 3018 and 3020 between the telecommunications network 3000 and the host computer 3016 may extend directly from the core network 3004 to the host computer 3016, or may occur through an optional intermediate network 3022. Intermediate network 3022 may be a combination of one or more of public, private, or managed networks; the intermediate network 3022, which may be a backbone network or the internet, if any; in particular, the intermediate network 3022 may include two or more sub-networks (not shown).

The communication system of fig. 30 as a whole implements connections between the connected UEs 3012, 3014 and the host computer 3016. The connection may be described as an Over-the-Top (OTT) connection 3024. The host computer 3016 and connected UEs 3012, 3014 are configured to communicate data and/or signaling using the access network 3002, the core network 3004, any intermediate networks 3022, and possibly other infrastructure (not shown) as intermediaries via OTT connection 3024. OTT connection 3024 may be transparent in the sense that the participating communication devices through which OTT connection 3024 passes are unaware of the routing of uplink and downlink communications. For example, the base station 3006 may not need or need to be informed of past routes of incoming downlink communications, where data originates from the host computer 3016 to be forwarded (e.g., handed over) to the connected UE 3012. Similarly, the base station 3006 need not be aware of the future routing of outgoing uplink communications from the UE3012 towards the host computer 3016.

An example implementation of the UE, base station and host computer discussed in the preceding paragraphs according to an embodiment will now be described with reference to fig. 31. In the communication system 3100, a host computer 3102 includes hardware 3104 including a communication interface 3106 configured to establish and maintain a wired or wireless connection with interfaces of different communication devices of the communication system 3100. The host computer 3102 also includes processing circuitry 3108, which may have storage and/or processing capabilities. In particular, the processing circuit 3108 may include one or more programmable processors, ASICs, FPGAs, or combinations thereof (not shown), which are adapted to execute instructions. The host computer 3102 also includes software 3110 that is stored in the host computer 3102 or is accessible by the host computer 3102 and executable by the processing circuit 3108. Software 3110 includes host applications 3112. The host application 3112 is operable to provide services to remote users, such as UE 3114 connected via OTT connection 3116 terminating at UE 3114 and host computer 3102. In providing services to remote users, the host application 3112 may provide user data that is sent using the OTT connection 3116.

The communication system 3100 further comprises a base station 3118 provided in the telecommunication system and comprising hardware 3120, which hardware 3120 enables communication with the host computer 3102 and the UE 3114. The hardware 3120 may include a communication interface 3122 for establishing and maintaining wired or wireless connections with interfaces of different communication devices of the communication system 3100, and a radio interface 3124 for establishing and maintaining at least a wireless connection 3126 with a UE 3114 located in a coverage area (not shown in fig. 31) served by the base station 3118. The communication interface 3122 may be configured to facilitate a connection 3128 to a host computer 3102. The connection 3128 may be direct or it may pass through a core network of the telecommunications system (not shown in fig. 31) and/or through one or more intermediate networks outside of the telecommunications system. In the illustrated embodiment, the hardware 3120 of the base station 3118 also includes processing circuitry 3130, which may include one or more programmable processors, ASICs, FPGAs, or a combination of these (not shown) adapted to execute instructions. The base station 3118 also has software 3132 stored internally or accessible via an external connection.

The communication system 3100 also comprises the already mentioned UE 3114. The hardware 3134 of the UE 3114 may include a radio interface 3136 configured to establish and maintain a wireless connection 3126 with a base station serving the coverage area in which the UE 3114 is currently located. The hardware 3134 of the UE 3114 also includes processing circuitry 3138, which may include one or more programmable processors, ASICs, FPGAs, or a combination of these (not shown) adapted to execute instructions. The UE 3114 also includes software 3140 stored in the UE 3114 or accessible by the UE 3114 and executable by the processing circuitry 3138. The software 3140 includes a client application 3142. The client application 3142 is operable to provide services to human or non-human users via the UE 3114 with the support of the host computer 3102. In the host computer 3102, the executing host application 3112 may communicate with the executing client application 3142 via an OTT connection 3116 that terminates at the UE 3114 and the host computer 3102. In providing services to the user, the client application 3142 may receive request data from the host application 3112 and provide user data in response to the request data. OTT connection 3116 may carry both request data and user data. The client application 3142 may interact with the user to generate the user data it provides.

Note that the host computer 3102, base station 3118, and UE 3114 shown in fig. 31 may be similar to or the same as one of the host computer 3016, base stations 3006A, 3006B, 3006C, and one of the UEs 3012, 3014, respectively, of fig. 30. That is, the internal operation of these entities may be as shown in fig. 31, and independently, the peripheral network topology may be as shown in fig. 30.

In fig. 31, the OTT connection 3116 has been abstractly drawn to illustrate communication between the host computer 3102 and the UE 3114 via the base station 3118 without explicit reference to any intermediate devices and the precise routing of messages via these devices. The network infrastructure may determine a route that may be configured to be hidden from the UE 3114 or from a service provider operating the host computer 3102, or both. When OTT connection 3116 is active, the network infrastructure may further make decisions by which to dynamically change routing (e.g., based on load balancing considerations or reconfiguration of the network).

The wireless connection 3126 between the UE 3114 and the base station 3118 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the UE 3114 using the OTT connection 3116, where the wireless connection 3126 forms the last leg. More specifically, the teachings of these embodiments may improve, for example, data rate, latency, power consumption, etc., thereby providing benefits such as reduced user latency, relaxed limitations on file size, better responsiveness, extended battery life, etc.

To monitor data rates, latency, and other factors for improvement in one or more embodiments, a measurement process may be provided. There may also be optional network functionality for reconfiguring the OTT connection 3116 between the host computer 3102 and the UE 3114 in response to changes in the measurement results. The measurement procedures and/or network functions for reconfiguring the OTT connection 3116 may be implemented in the software 3110 and hardware 3104 of the host computer 3102 or in the software 3140 and hardware 3134 or both of the UE 3114. In some embodiments, sensors (not shown) may be disposed in or associated with the communication devices through which OTT connection 3116 passes; the sensor may participate in the measurement process by providing the values of the monitored quantities exemplified above or providing values of other physical quantities that the software 3110, 3140 may calculate or estimate the monitored quantities. The reconfiguration of OTT connection 3116 may include message format, retransmission settings, preferred routing, etc.; the reconfiguration need not affect base station 3118 and may be unknown or imperceptible to base station 3118. Such processes and functions may be known and practiced in the art. In certain embodiments, the measurements may involve proprietary UE signaling that facilitates the measurement of throughput, propagation time, delay, etc. by the host computer 3102. Measurements may be made by the software 3110 and 3140 using the OTT connection 3116 to transmit messages, particularly null or 'dummy' messages, while monitoring propagation times, errors, etc.

Fig. 32 is a flow diagram illustrating a method implemented in a communication system in accordance with one embodiment. The communication system includes a host computer, base stations and UEs, which may be those described with reference to fig. 30 and 31. For simplicity of the invention, this section will include only the drawing reference to FIG. 32. In step 3200, the host computer provides user data. In sub-step 3202 of step 3200 (which may be optional), the host computer provides user data by executing a host application. In step 3204, the host computer initiates transmission of bearer user data to the UE. In step 3206 (which may be optional), the base station sends user data carried in the host computer initiated transmission to the UE in accordance with the teachings of the embodiments described throughout this disclosure. In step 3208 (which may also be optional), the UE executes a client application associated with a host application executed by a host computer.

Fig. 33 is a flow diagram illustrating a method implemented in a communication system in accordance with one embodiment. The communication system includes a host computer, base stations and UEs, which may be those described with reference to fig. 30 and 31. For simplicity of the invention, this section will include only the drawing reference to FIG. 33. In step 3300 of the method, the host computer provides user data. In an optional sub-step (not shown), the host computer provides user data by executing a host application. In step 3302, the host computer initiates transmission of bearer user data to the UE. According to the teachings of the embodiments described throughout this disclosure, transmission may be via a base station. In step 3304 (which may be optional), the UE receives user data carried in the transmission.

Fig. 34 is a flow diagram illustrating a method implemented in a communication system in accordance with one embodiment. The communication system includes a host computer, base stations and UEs, which may be those described with reference to fig. 30 and 31. For simplicity of the invention, this section will include only the drawing reference to FIG. 34. In step 3400 (which may be optional), the UE receives input data provided by the host computer. Additionally or alternatively, in step 3402, the UE provides user data. In sub-step 3404 (which may be optional) of step 3400, the UE provides user data by executing a client application. In sub-step 3406 (which may be optional) of step 3402, the UE executes a client application that provides user data in response to received input data provided by the host computer. The executing client application may further consider user input received from the user in providing the user data. Regardless of the particular manner in which the user data is provided, the UE initiates transmission of the user data to the host computer in sub-step 3408 (which may be optional). In step 3410 of the method, the host computer receives user data transmitted from the UE in accordance with the teachings of the embodiments described throughout this disclosure.

Fig. 35 is a flow diagram illustrating a method implemented in a communication system in accordance with one embodiment. The communication system includes a host computer, a base station, and a UE, which may be those described with reference to fig. 30 and 31. For simplicity of the invention, this section will include only the figure reference to FIG. 35. In step 3500 (which may be optional), the base station receives user data from the UE according to the teachings of embodiments described throughout this disclosure. In step 3502 (which may be optional), the base station initiates transmission of the received user data to the host computer. In step 3504 (which may be optional), the host computer receives user data carried in transmissions originated by the base station.

Any suitable steps, methods, features, functions or benefits disclosed herein may be performed by one or more functional units or modules of one or more virtual devices. Each virtual device may include a plurality of such functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessors or microcontrollers, as well as other digital hardware, which may include Digital Signal Processors (DSPs), dedicated digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or more types of memory, such as Read Only Memory (ROM), random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, and the like. The program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols and instructions for performing one or more of the techniques described herein. In some implementations, the processing circuitry may be operative to cause the respective functional units to perform corresponding functions in accordance with one or more embodiments of the present invention.

Although the processes in the figures may show a particular order of operations performed by certain embodiments of the invention, it should be understood that such order is exemplary (e.g., alternative embodiments may perform the operations in a different order, combine certain operations, overlap certain operations), etc.

Examples

Group A examples

Example 1: a method performed by a wireless device for determining a transmission configuration indication, TCI, status for receiving one or more aperiodic AP channel state information reference signals, CSI-RS, the method comprising one or more of: receiving (1300) one or more AP CSI-RSs in the same symbol as a downlink transmission scheduled by a DCI having two TCI states indicated in the DCI; receiving (1302) a trigger for one or more AP CSI-RSs having a scheduling offset between a last symbol of a PDCCH carrying the trigger DCI and a first symbol of an AP CSI-RS resource, wherein the scheduling offset is less than a threshold reported by a wireless device; and determining (1304) that the downlink transmission is scheduled according to one of the group consisting of: "TDM scheme A"; "FDM scheme a"; "FDM scheme B"; and schemes in which different layer sets of downlink transmissions are received in different TCI states.

Example 2: the method of any preceding embodiment, wherein the downlink transmission comprises a physical downlink shared channel, PDSCH, transmission.

Example 3: the method of any preceding embodiment, wherein the threshold reported by the wireless device comprises a beamSwitchTiming value.

Example 4: the method of any preceding embodiment, wherein the PDSCH is scheduled according to one of the group consisting of: "FDM scheme a"; "FDM scheme B"; and schemes to receive different layer sets of PDSCH in different TCI states.

Example 5: the method of any preceding embodiment, wherein the scheduling offset from the last symbol of the PDCCH to the first symbol of the PDSCH is greater than or equal to a threshold timedutionformqcl.

Example 6: the method of any of the preceding embodiments further comprising: applying (1306) a quasi co-located QCL hypothesis given by a first indication TCI status in DCI of PDSCH when the single triggered AP CSI-RS is in the same symbol as the PDSCH when the AP CSI-RS is received.

Example 7: the method of any of the preceding embodiments further comprising: applying (1306) QCL hypotheses given by a first indication TCI state and a second indication TCI state in DCI of PDSCH, respectively, when the two triggered AP CSI-RS are in the same symbol as the PDSCH, when receiving the first AP CSI-RS and the second AP CSI-RS.

Example 8: the method of any of the preceding embodiments, wherein the first triggered AP CSI-RS and the second triggered AP CSI-RS are according to an ordering of the corresponding CSI-RS resource identifiers or an ordering of the corresponding CSI-RS resource set identifiers to which the two AP CSI-RSs belong.

Example 9: the method of any preceding embodiment, wherein a scheduling offset from a last symbol of the PDCCH to a first symbol of the PDSCH is less than a threshold timedutionformqcl.

Example 10: the method of any of the preceding embodiments further comprising: applying (1306) QCL assumptions given by a first default TCI state for PDSCH when the single triggered AP CSI-RS is in the same symbol as the PDSCH when the AP CSI-RS is received.

Example 11: the method of any of the preceding embodiments further comprising: applying (1306) QCL assumptions given by the first and second default TCI states for the PDSCH when the two triggered AP CSI-RS are in the same symbol as the PDSCH when receiving the first and second AP CSI-RS, respectively.

Example 12: the method of any of the preceding embodiments, wherein the first triggered AP CSI-RS and the second triggered AP CSI-RS are according to an ordering of the corresponding CSI-RS resource identifiers or an ordering of the corresponding CSI-RS resource set identifiers to which the two AP CSI-RSs belong.

Example 13: the method according to any of the preceding embodiments, wherein the PDSCH is scheduled according to a "TDM scheme a".

Example 14: the method of any preceding embodiment, wherein a scheduling offset from a last symbol of a PDCCH to a first symbol of a first PDSCH transmission occasion is greater than or equal to a threshold timeDurationForQCL.

Example 15: the method of any of the preceding embodiments further comprising: applying (1306) a QCL assumption given by a first indication TCI state in DCI of a first PDSCH transmission occasion when the single triggered AP CSI-RS is in the same symbol as the first PDSCH transmission occasion when the AP CSI-RS is received.

Example 16: the method of any of the preceding embodiments further comprising: applying (1306) the QCL hypothesis given by the second indication TCI state in the DCI of the second PDSCH transmission occasion when the single triggered AP CSI-RS is in the same symbol as the second PDSCH transmission occasion when the AP CSI-RS is received.

Example 17: the method of any preceding embodiment, wherein a scheduling offset from a last symbol of a PDCCH to a first symbol of both a first PDSCH transmission occasion and a second PDSCH transmission occasion is less than a threshold timeduration for qcl.

Example 18: the method of any of the preceding embodiments further comprising: applying (1306) the QCL assumption given by a first default TCI state in DCI of a first PDSCH transmission occasion when a single triggered AP CSI-RS is in the same symbol as the first PDSCH transmission occasion when the AP CSI-RS is received.

Example 19: the method of any of the preceding embodiments further comprising: applying (1306) the QCL hypothesis given by the second indication TCI state in the DCI of the second PDSCH transmission occasion when the single triggered AP CSI-RS is in the same symbol as the second PDSCH transmission occasion when the AP CSI-RS is received.

Example 20: the method of any of the preceding embodiments, further comprising: providing user data; and forwarding the user data to the host computer via transmission to the base station.

Group B examples

Example 21: a method performed by a base station for indicating a transmission configuration indication, TCI, status for receiving one or more aperiodic AP channel state information reference signals, CSI-RS, the method comprising one or more of: transmitting (1400), to the wireless device, one or more AP CSI-RSs in the same symbol as a downlink transmission scheduled by the DCI with two TCI states indicated in the DCI; triggering (1402) one or more AP CSI-RS having a scheduling offset between a last symbol of a PDCCH carrying the triggered DCI and a first symbol of an AP CSI-RS resource, wherein the scheduling offset is less than a threshold reported by the wireless device; and scheduling (1404) downlink transmissions according to one of the group consisting of: "TDM scheme A"; "FDM scenario a"; "FDM scheme B"; and schemes in which different layer sets of downlink transmissions are received in different TCI states.

Example 22: the method according to any of the preceding embodiments, wherein the downlink transmission comprises a physical downlink shared channel, PDSCH, transmission.

Example 23: the method of any preceding embodiment, wherein the threshold reported by the wireless device comprises a beamSwitchTiming value.

Example 24: the method according to any of the preceding embodiments, wherein the PDSCH is scheduled according to one of the group consisting of: "FDM scheme a"; "FDM scheme B"; and schemes to receive different layer sets of PDSCH in different TCI states.

Example 25: the method of any preceding embodiment, wherein a scheduling offset from a last symbol of the PDCCH to a first symbol of the PDSCH is greater than or equal to a threshold timedurationformqcl.

Example 26: the method of any of the preceding embodiments further comprising: when the single triggered AP CSI-RS is in the same symbol as the PDSCH, assume (1406) that the wireless device applies the quasi-co-located QCL assumption given by the first indication TCI status in the DCI of the PDSCH when receiving the AP CSI-RS.

Example 27: the method of any of the preceding embodiments further comprising: when the two triggered AP CSI-RS are in the same symbol as the PDSCH, assume (1406) that the wireless device applies the QCL hypothesis given by the first and second indication TCI states in the DCI of the PDSCH, respectively, when receiving the first and second AP CSI-RS.

Example 28: the method of any of the preceding embodiments, wherein the first triggered AP CSI-RS and the second triggered AP CSI-RS are according to an ordering of the corresponding CSI-RS resource identifiers or an ordering of the corresponding CSI-RS resource set identifiers to which the two AP CSI-RSs belong.

Example 29: the method of any preceding embodiment, wherein a scheduling offset from a last symbol of the PDCCH to a first symbol of the PDSCH is less than a threshold timedutionformqcl.

Example 30: the method of any of the preceding embodiments further comprising: when the single triggered AP CSI-RS is in the same symbol as the PDSCH, it is assumed (1406) that the wireless device applies a QCL assumption given by a first default TCI state of the PDSCH when receiving the AP CSI-RS.

Example 31: the method of any of the preceding embodiments further comprising: when the two triggered AP CSI-RSs are in the same symbol as the PDSCH, it is assumed (1406) that the wireless device applies QCL assumptions given by the first and second default TCI states of the PDSCH when receiving the first and second AP CSI-RSs, respectively.

Example 32: the method of any of the preceding embodiments, wherein the first triggered AP CSI-RS and the second triggered AP CSI-RS are according to an ordering of the corresponding CSI-RS resource identifiers or an ordering of the corresponding CSI-RS resource set identifiers to which the two AP CSI-RSs belong.

Example 33: the method of any preceding embodiment, wherein the PDSCH is scheduled according to "TDM scheme a".

Example 34: the method of any preceding embodiment, wherein a scheduling offset from a last symbol of a PDCCH to a first symbol of a first PDSCH transmission occasion is greater than or equal to a threshold timeduration format.

Example 35: the method of any of the preceding embodiments further comprising: when the single triggered AP CSI-RS is in the same symbol as the first PDSCH transmission occasion, assume (1406) that the wireless device applies a QCL assumption given by a first indication, TCI, state in DCI of the first PDSCH transmission occasion when receiving the AP CSI-RS.

Example 36: the method of any of the preceding embodiments further comprising: when the single triggered AP CSI-RS is in the same symbol as the second PDSCH transmission occasion, assume (1406) that the wireless device applies a QCL assumption given by a second indication, TCI, state in DCI of the second PDSCH transmission occasion when receiving the AP CSI-RS.

Example 37: the method of any preceding embodiment, wherein a scheduling offset from a last symbol of a PDCCH to a first symbol of both a first PDSCH transmission occasion and a second PDSCH transmission occasion is less than a threshold timeduration for qcl.

Example 38: the method of any of the preceding embodiments further comprising: when the single triggered AP CSI-RS is in the same symbol as the first PDSCH transmission occasion, assume (1406) that the wireless device applies a QCL assumption given by a first default TCI state in DCI of the first PDSCH transmission occasion when receiving the AP CSI-RS.

Example 39: the method of any of the preceding embodiments further comprising: when the single triggered AP CSI-RS is in the same symbol as the second PDSCH transmission occasion, assuming (1406) that the wireless device applies a QCL assumption given by a second indicated TCI state in the DCI of the second PDSCH transmission occasion when receiving the AP CSI-RS.

Example 40: the method of any of the preceding embodiments, further comprising: acquiring user data; and forwarding the user data to the host computer or wireless device.

Group C examples

Example 41: a wireless device for determining a transmission configuration indication, TCI, status for receiving one or more aperiodic AP channel state information reference signals, CSI-RS, the wireless device comprising: processing circuitry configured to perform any of the steps of any of the group a embodiments; and a power circuit configured to supply power to the wireless device.

Example 42: a base station for indicating a transmission configuration indication, TCI, status for receiving one or more aperiodic AP channel state information reference signals, CSI-RS, the base station comprising: processing circuitry configured to perform any of the steps of any of the group B embodiments; and a power supply circuit configured to supply power to the base station.

Example 43: a user equipment, UE, for determining a transmission configuration indication, TCI, status for receiving one or more aperiodic AP channel state information reference signals, CSI-RS, the UE comprising: an antenna configured to transmit and receive wireless signals; a radio front-end circuit connected to the antenna and the processing circuit and configured to condition signals communicated between the antenna and the processing circuit; processing circuitry configured to perform any of the steps of any of group A embodiments; an input interface connected to the processing circuitry and configured to allow information to be input into the UE for processing by the processing circuitry; an output interface connected to the processing circuitry and configured to output information processed by the processing circuitry from the UE; and a battery connected to the processing circuitry and configured to power the UE.

Example 44: a communication system including a host computer, comprising: processing circuitry configured to provide user data; a communication interface configured to forward user data to a cellular network for transmission to a user equipment, UE; wherein the cellular network comprises a base station having a radio interface and processing circuitry, the processing circuitry of the base station being configured to perform any of the steps of any of the group B embodiments.

Example 45: the communication system according to the foregoing embodiment, further comprising a base station.

Example 46: the communication system according to the 2 previous embodiments, further comprising a UE, wherein the UE is configured to communicate with the base station.

Example 47: the communication system according to the preceding 3 embodiments, wherein: processing circuitry of the host computer is configured to execute the host application, thereby providing user data; and the UE includes processing circuitry configured to execute a client application associated with the host application.

Example 48: a method implemented in a communication system comprising a host computer, a base station, and a user equipment, UE, the method comprising: at a host computer, providing user data; and at the host computer, initiating transmission of a user data bearer to the UE via a cellular network comprising a base station, wherein the base station performs any of the steps of any of the group B embodiments.

Example 49: the method of the preceding embodiment, further comprising transmitting user data at the base station.

Example 50: the method of the preceding 2 embodiments, wherein the user data is provided at the host computer by executing the host application, the method further comprising executing a client application associated with the host application at the UE.

Example 51: a user equipment, UE, configured to communicate with a base station, the UE comprising a radio interface and processing circuitry configured to perform the methods of the 3 preceding embodiments.

Example 52: a communication system including a host computer, comprising: processing circuitry configured to provide user data; and a communication interface configured to forward user data to the cellular network for transmission to the user equipment, UE; wherein the UE comprises a radio interface and processing circuitry, the components of the UE being configured to perform any of the steps of any of the group a embodiments.

Example 53: the communication system of the preceding embodiment, wherein the cellular network further comprises a base station configured to communicate with the UE.

Example 54: the communication system according to the preceding 2 embodiments, wherein: processing circuitry of the host computer is configured to execute the host application, thereby providing user data; and the processing circuitry of the UE is configured to execute a client application associated with the host application.

Example 55: a method implemented in a communication system comprising a host computer, a base station, and a user equipment, UE, the method comprising: at a host computer, providing user data; and at the host computer, initiating transmission of a user data bearer to the UE via a cellular network comprising the base station, wherein the UE performs any of the steps of any of the group a embodiments.

Example 56: the method of the preceding embodiment, further comprising receiving, at the UE, user data from the base station.

Example 57: a communication system including a host computer, comprising: a communication interface configured to receive user data originating from a transmission from a user equipment, UE, to a base station; wherein the UE comprises a radio interface and processing circuitry, the processing circuitry of the UE configured to perform any of the steps of any of the group a embodiments.

Example 58: the communication system according to the previous embodiment, further comprising a UE.

Example 59: the communication system of the preceding 2 embodiments, further comprising a base station, wherein the base station comprises a wireless interface for communicating with the UE and a communication interface configured to forward user data carried by transmissions from the UE to the base station to the host computer.

Example 60: the communication system according to the preceding 3 embodiments, wherein: processing circuitry of the host computer is configured to execute a host application; and the processing circuitry of the UE is configured to execute a client application associated with the host application to provide the user data.

Example 61: the communication system according to the preceding 4 embodiments, wherein: processing circuitry of the host computer is configured to execute the host application, thereby providing the requested data; and the processing circuitry of the UE is configured to execute a client application associated with the host application to provide the user data in response to the request data.

Example 62: a method implemented in a communication system comprising a host computer, a base station, and a user equipment, UE, the method comprising: at the host computer, user data transmitted from the UE to the base station is received, wherein the UE performs any of the steps of any of the group a embodiments.

Example 63: the method of the preceding embodiment, further comprising providing, at the UE, the user data to the base station.

Example 64: the method according to the preceding 2 embodiments, further comprising: at the UE, executing a client application, thereby providing user data to be transmitted; and executing, on the host computer, a host application associated with the client application.

Example 65: the method according to the preceding 3 embodiments, further comprising: at the UE, executing a client application; and at the UE, receiving input data for the client application, the input data provided at the host computer by executing a host application associated with the client application; wherein the user data to be transmitted is provided by the client application in response to the input data.

Example 66: a communication system comprising a host computer comprising a communication interface configured to receive user data originating from a transmission from a user equipment, UE, to a base station, wherein the base station comprises a radio interface and processing circuitry, the processing circuitry of the base station being configured to perform any of the steps of any of the group B embodiments.

Example 67: the communication system according to the preceding embodiment, further comprising a base station.

Example 68: the communication system according to the preceding 2 embodiments, further comprising a UE, wherein the UE is configured to communicate with a base station.

Example 69: the communication system according to the preceding 3 embodiments, wherein: processing circuitry of the host computer is configured to execute a host application; and the UE is configured to execute a client application associated with the host application, thereby providing user data to be received by the host computer.

Example 70: a method implemented in a communication system comprising a host computer, a base station, and a user equipment, UE, the method comprising: at the host computer, receiving, from the base station, user data originating from a transmission that the base station has received from a UE, wherein the UE performs any of the steps set forth in any of the group a embodiments.

Example 71: the method of the preceding embodiment, further comprising receiving, at the base station, user data from the UE.

Example 72: the method of the preceding 2 embodiments, further comprising initiating, at the base station, transmission of the received user data to the host computer.

At least some of the following abbreviations may be used in the present invention. If there is inconsistency between abbreviations, the above usage should be prioritized. If listed multiple times below, the first list should be prioritized over any subsequent lists.

3GPP third Generation partnership project

5G fifth Generation

5GC fifth Generation cores

5GS fifth Generation System

AF application function

AMF access and mobility management functions

AN Access network

AP Access Point

ASIC specific integrated circuit

AUSF authentication Server function

CPU central processing unit

DN data network

DSP digital signal processor

eNB enhanced or evolved node B

Packet system for EPS evolution

E-UTRA evolved universal terrestrial radio access

FPGA field programmable Gate array

gNB new radio base station

gNB-DU New radio base station distributed Unit

HSS Home subscriber Server

IoT Internet of things

IP Internet protocol

LTE Long term evolution

MME mobility management entity

MTC machine type communication

NEF network open function

NF network functionality

NR new radio

NRF network function storage function

NSSF network slice selection function

OTT overhead (Over-the-Top)

PC personal computer

PCF policy control function

P-GW packet data network gateway

QoS quality of service

RAM random access memory

RAN radio Access network

ROM read-only memory

RRH remote radio head

RTT round trip time

SCEF service capability opening function

SMF session management function

UDM unified data management

UE user Equipment

UPF user plane functionality

Those skilled in the art will recognize improvements and modifications to embodiments of the present invention. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims (50)

1. A method performed by a wireless device for determining a transmission configuration indication, TCI, status for receiving one or more aperiodic AP channel state information reference signals, CSI-RS, the method comprising:

receiving (1300) one or more AP CSI-RSs in one or more symbols, and receiving (1300) one or more downlink transmissions associated with a plurality of TCI states in the same one or more symbols;

receiving (1302) downlink control information, DCI, in a physical downlink control channel, PDCCH, the DCI triggering the one or more AP CSI-RSs with a first time offset between a last symbol of the PDCCH and a first symbol of the AP CSI-RSs, wherein the time offset is less than a first threshold;

determining (1304), based on the plurality of TCI states, a quasi-co-located QCL hypothesis for receiving the one or more AP CSI-RSs; and

receiving the one or more AP CSI-RSs using the determined QCL hypothesis.

2. The method of claim 1, wherein the one or more downlink transmissions comprise one or more Physical Downlink Shared Channel (PDSCH) transmissions.

3. The method of claim 2, wherein the PDSCH is scheduled by DCI carried in a PDCCH.

4. The method of any of claims 2 to 3, wherein a second time offset between a first symbol of the DCI carrying a scheduled PDSCH in the PDCCH and a first symbol of the PDSCH is greater than or equal to a second threshold.

5. The method of any one of claims 1-4, wherein each of the one or more downlink transmissions is associated with one of the plurality of TCI states.

6. The method of any of claims 1-5, wherein the one or more downlink transmissions are one or more PDSCH repetitions in the time domain or in the frequency domain.

7. The method of claim 6, wherein the one or more downlink transmissions are according to one of a scheme "TDM scheme A", "FDM scheme B", or "FDM scheme A".

8. The method of any of claims 1-5, wherein the one or more downlink transmissions are one or more layer sets of PDSCH, wherein each layer set is associated with one of the plurality of TCI states.

9. The method of any of claims 1-8, wherein the plurality of TCI states are indicated in the DCI scheduling the one or more PDSCH transmissions.

10. The method of any one of claims 1 to 8, wherein the plurality of TCI states includes a first TCI state and a second TCI state.

11. The method of claim 1, wherein the one or more symbols are one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols.

12. The method of any of claims 1-11, wherein the first threshold comprises a beamSwitchTiming value reported by the wireless device.

13. The method of any of claims 1-12, wherein the second threshold is a timeDurationForQCL value reported by the wireless device.

14. The method of claims 1 to 13, wherein determining a quasi-co-located QCL hypothesis for receiving the one or more AP CSI-RSs based on the plurality of TCI states comprises:

applying (1306) QCL assumptions given by a first indicated TCI state in the DCI for the PDSCH in a symbol for receiving the one or more AP CSI-RSs in the same symbol when the one or more downlink transmissions are one or more layer sets of the PDSCH and wherein each layer set is associated with one of the plurality of TCI states.

15. The method of any of claims 1 to 13, wherein determining a quasi-co-located QCL hypothesis for receiving the one or more AP CSI-RSs based on the plurality of TCI states further comprises:

applying (1306) QCL assumptions given by the TCI states of the one or more PDSCH transmissions in a symbol for receiving the one or more AP CSI-RSs in the same symbol when the one or more downlink PDSCH transmissions are one or more PDSCH repetitions in a time domain and each of the one or more PDSCH transmissions is associated with one of the plurality of TCI states.

16. The method of any of claims 1 to 13, wherein determining a quasi-co-located QCL hypothesis for receiving the one or more AP CSI-RSs based on the plurality of TCI states further comprises:

applying (1306) QCL assumptions given by a first TCI state of the plurality of TCI states for receiving the one or more AP CSI-RSs.

17. The method of any of claims 1-12, wherein the second offset is less than the threshold timeDurationForQCL.

18. The method of any one of claims 1 to 17, wherein the plurality of TCI states includes a first default TCI state and a second default TCI state, wherein the first default TCI state and the second default TCI state are associated with a codepoint of a TCI field in DCI having a lowest codepoint value.

19. The method of claim 18, further comprising:

applying (1306) the QCL assumption given by the first default TCI state for the PDSCH when a single triggered AP CSI-RS is in the same symbol as PDSCH when the AP CSI-RS is received.

20. The method of any of claims 17 to 19, further comprising:

applying (1306) the QCL assumptions given by the first and second default TCI states for the PDSCH when the two triggered AP CSI-RS are in the same symbol as the PDSCH with which the first and second TCI states are associated, when receiving the first and second AP CSI-RS, respectively.

21. A method performed by a base station for indicating a transmission configuration indication, TCI, status for receiving one or more aperiodic AP channel state information reference signals, CSI-RS, the method comprising:

signaling to a wireless device one or more AP CSI-RSs to be transmitted to the wireless device in one or more symbols in downlink control information, DCI, in a physical control channel, PDCCH, wherein one or more downlink transmissions associated with two TCI states will also be transmitted in the same symbol;

determining a quasi co-located QCL hypothesis for transmitting the one or more AP CSI-RSs based on the TCI status of the one or more downlink transmissions; and

transmitting (1400), to the wireless device, the one or more AP CSI-RSs in the one or more symbols according to the QCL hypothesis.

22. The method of claim 21, wherein a first time offset between the PDCCH and the one or more AP CSI-RSs is less than or equal to a first threshold.

23. The method of any of claims 21 to 22, wherein the one or more downlink transmissions comprise Physical Downlink Shared Channel (PDSCH) transmissions.

24. The method of any of claims 21-23, wherein the PDSCH is scheduled by a DCI format carried in a PDCCH.

25. The method of any of claims 21-24, wherein a second time offset between the PDCCH and the PDSCH is greater than or equal to a second threshold.

26. The method of any one of claims 214-25, wherein the first threshold and the second threshold are signaled to the wireless device.

27. The method of any one of claims 21-26, wherein each of the one or more downlink transmissions is associated with one of the two TCI states.

28. The method of any of claims 21-27, wherein the one or more downlink transmissions are one or more PDSCH repetitions in the time domain.

29. The method of any of claims 21-28, wherein the one or more downlink transmissions are one or more layer sets of PDSCH, wherein each layer set is associated with one of the two TCI states.

30. The method of any one of claims 21 to 29, wherein the two TCI states are indicated in the DCI that schedules the one or more PDSCH transmissions.

31. The method of any one of claims 21 to 30, wherein the two TCI states comprise a first TCI state and a second TCI state.

32. The method of any one of claims 21-31, wherein the one or more symbols are one or more Orthogonal Frequency Division Multiplexing (OFDM) symbols.

33. The method of any of claims 21-32, wherein the first threshold comprises a beamSwitchTiming value reported by the wireless device.

34. The method of any of claims 21-33, wherein the second threshold comprises a timedurationformqcl value reported by the wireless device.

35. The method of claims 21-34, wherein determining a quasi-co-located QCL hypothesis for sending the one or more AP CSI-RSs based on the TCI status of the one or more downlink transmissions comprises:

applying QCL assumptions given by the first TCI state of the PDSCH for transmitting the one or more APCSI-RSs when the one or more downlink transmissions are one or more layer sets of the PDSCH and each layer set is associated with one of the two TCI states.

36. The method of any of claims 21 to 35, wherein determining a quasi-co-located QCL hypothesis for transmitting the one or more AP CSI-RSs based on the TCI status of the one or more downlink transmissions further comprises:

applying QCL assumptions given by the TCI states of the one or more PDSCH transmissions in a symbol for transmitting the one or more AP CSI-RSs in the same symbol when the one or more downlink PDSCH transmissions are one or more PDSCH repetitions in a time domain and each of the one or more PDSCH transmissions is associated with one of the two TCI states.

37. The method of any of claims 21 to 34, wherein determining a quasi-co-located QCL hypothesis for transmitting the one or more AP CSI-RSs based on the TCI status of the one or more downlink transmissions further comprises:

applying QCL assumptions given by the first of the two TCI states for transmitting the one or more AP CSI-RSs.

38. The method of any of claims 21-34, wherein the second offset is less than the second threshold timedutionformqcl.

39. The method of any one of claims 21-38, wherein the two TCI states comprise a first default TCI state and a second default TCI state, wherein the first default TCI state and the second default TCI state are associated with codepoints of a TCI field in DCI having a lowest codepoint value.

40. The method of any of claims 38 to 39, further comprising:

applying the QCL assumption given by the first default TCI state for the PDSCH when a single triggered AP CSI-RS is in the same symbol as PDSCH when the AP CSI-RS is transmitted.

41. The method of any of claims 38 to 40, further comprising:

applying the QCL assumption given by the first and second default TCI states for the PDSCH when the two triggered AP CSI-RS are in the same symbol as the PDSCH when the first and second AP CSI-RS are transmitted separately.

42. The method of any one of claims 21-41, wherein the default TCI state for the one or more downlink transmissions is given by the TCI state corresponding to a lowest of the TCI codepoints that includes two different TCI states.

43. A wireless device (2800) for activating a transport configuration indicator, TCI, state, adapted to perform:

receiving one or more AP CSI-RSs in one or more symbols and one or more downlink transmissions having a plurality of TCI states scheduled by the DCI in the same one or more symbols;

receiving downlink control information, DCI, in a physical downlink control channel, PDCCH, the DCI triggering the one or more AP CSI-RSs with a first time offset between a last symbol of the PDCCH carrying the triggering DCI and a first symbol of the AP CSI-RS resource, wherein the first time offset is less than a threshold reported by a wireless device; and

determining a quasi-co-located QCL hypothesis for receiving the one or more AP CSI-RSs based on the plurality of TCI states.

44. The wireless device (2800) of claim 43, wherein the wireless device (2800) is further adapted to perform the method of any of claims 2 to 20.

45. A wireless device (2800) for activating a transport configuration indicator, TCI, state, comprising:

one or more transmitters (2808);

one or more receivers (2810); and

a processing circuit (2802) associated with the one or more transmitters (2808) and the one or more receivers (2810), the processing circuit (2802) configured to cause the wireless device (2800) to:

receiving one or more AP CSI-RSs in the same symbol as receiving one or more downlink transmissions scheduled by the DCI having two indicated TCI states;

receiving a trigger for the one or more AP CSI-RS with a scheduling offset between a last symbol of a PDCCH carrying the triggering DCI and a first symbol of an AP CSI-RS resource, wherein the scheduling offset is less than a threshold reported by a wireless device; and

determining a quasi co-located QCL hypothesis for receiving the one or more AP CSI-RSs based on the TCI status.

46. The wireless device (2800) of claim 45, wherein the processing circuit (2802) is further configured to cause the wireless device (2800) to perform the method of any of claims 2 to 20.

47. A base station (2500) for activating a transmission configuration indicator, TCI, state, adapted to perform:

signaling to a wireless device one or more AP CSI-RSs to be transmitted to the wireless device in one or more symbols in downlink control information, DCI, in a physical control channel, PDCCH, wherein one or more downlink transmissions associated with two TCI states will also be transmitted in the same symbol;

determining a quasi-co-located QCL hypothesis for transmitting the one or more AP CSI-RSs based on the TCI status of the one or more downlink transmissions; and

transmitting one or more AP CSI-RSs to a wireless device according to the QCL hypothesis.

48. The base station (2500) of claim 47, wherein the base station (2500) is further adapted to perform the method of any one of claims 22 to 42.

49. A base station (2500) for activating a transmission configuration indicator, TCI, state, comprising:

one or more transmitters (2512);

one or more receivers (2514); and

processing circuitry (2504) associated with the one or more transmitters (2512) and the one or more receivers (2514), the processing circuitry (2504) configured to cause the base station (2500) to perform:

signaling to a wireless device one or more AP CSI-RSs to be transmitted to the wireless device in one or more symbols in downlink control information, DCI, in a physical control channel, PDCCH, wherein one or more downlink transmissions associated with two TCI states will also be transmitted in the same symbol;

determining a quasi co-located QCL hypothesis for transmitting the one or more AP CSI-RSs based on the TCI status of the one or more downlink transmissions; and

transmitting the one or more AP CSI-RSs to the wireless device in the one or more symbols according to the QCL hypothesis.

50. The base station (2500) of claim 49, wherein the processing circuitry (2504) is further configured to cause the base station (2500) to perform the method of any one of claims 22-42.

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